batch file or some other automation script for simple-ish file operation

This copies all files having a "001440" filename suffix.
Target folders are created based on source file folder.

Make a .bat of this. Change the value after the = for RootDir, CopyToDir, Sequence to your needs:

set RootDir=C:\Local\test\dir
set CopyToDir=C:\Local\test\copyto
set Sequence=001440
xcopy /s "%RootDir%\bmpcc   *_%Sequence%.dng" "%CopyToDir%"

Select allOpen in new window

I think you misunderstood, I meant every 1440th file in directory, so for example, based on example filenames I posted...

bmpcc   001_1_2015-09-17_0400_C0005_000000.dng
bmpcc   001_1_2015-09-17_0400_C0005_001440.dng
bmpcc   001_1_2015-09-17_0400_C0005_002880.dng
bmpcc   001_1_2015-09-17_0400_C0005_003960.dng

and so on, as long as the file exists, I would also like to be able to easily change the increment from 1440 to something else, for example 6000

each directory will have vastly different number of files so before copying script needs to check if file with that name exists and if it doesn't skip to next directory and stop over, from 1440 for example...

again, only a single file will match these answers, I'm looking for a batch file or whatever that may be that will copy files with multiples of the number 1440 in the name, or whatever other number I may set, plus it would need to traverse all subdirectories under specified root directory and in each directory do the same, copy all existing files with multiplied number 1440 in their name

Here's a batch that copies every nth file (not necessarily multiplies, if the numbers aren't contiguous). It's currently in test mode and will only display the files it would copy; remove the REM in line 13 to run it for real.

@echo off
setlocal enabledelayedexpansion
set Source=C:\Temp\Takes
set Target=C:\Temp\Target
set Increment=1440
set Mask=*.dng
for /f "delims=" %%a in ('dir /b /a:d /o:n "%Source%\*.*"') do (
	echo Processing %%a ...
	set /a Index = %Increment%
	for /f "delims=" %%b in ('dir /b /a:-d /o:n "%Source%\%%a\%Mask%"') do (
		if !Index!==%Increment% (
			echo 	- '%%b'
			REM copy "%Source%\%%a\%%b" "%Target%"
			set /a Index = 1
		) else (
			set /a Index += 1
		)
	)
)

Select allOpen in new window

I tried the powershell script and here is what happens

PS C:\Users\user> gci "I:\Rob day 1\bmpcc   001_1_2015-09-17_0341_C0001" -File -Recurse | ?([int]$_.Name.Substring($_.Na
me.Length - 6, 6) % 1440 -eq 0) | Copy-Item $_.FullLength "I:\stills\"+$_.Name
You cannot call a method on a null-valued expression.
At line:1 char:1
+ gci "I:\Rob day 1\bmpcc   001_1_2015-09-17_0341_C0001" -File -Recurse ...
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : InvalidOperation: (:) [], RuntimeException
    + FullyQualifiedErrorId : InvokeMethodOnNull

$Source = "C:\temp\Takes\*.dng"
$Target = "C:\temp\Target"
$Increment = 1440
Get-ChildItem -Path $Source -File -Recurse |
      Where-Object {
            ($_.BaseName.Split("_")[-1] % $Increment) -eq 0
      } |
      ForEach-Object {
            Copy-Item -Path $_.FullName -Destination $Target -WhatIf
      }

will this one also traverse all subdirectiories under takes? so for example C:\temp\Takes\1\, C:\temp\Takes\2\, C:\temp\Takes\3\ and so on?

Yes, that's what the "-Recurse" does (or -R in the condensed version).
You can just run it as it is, it will only generate console output for the files it would copy as long as Copy-Item has the -WhatIf argument.
Or replace the "Copy-Item ..." line with Write-Host $_.FullName, which makes the output more readable than the -WhatIf.

now you got me confused, sorry, could you post the full script with the modifications you mentioned? I've never used the PS script in my life...

I don't think it works, what am I doing wrong?

PS C:\Users\user> $Source = "I:\rob day 22\*.dng" |$Target = "I:\stills\" | $Increment = 1440 | Get-ChildItem -Path
$Source -File -Recurse | Where-Object { | ($_.BaseName.Split("_")[-1] % $Increment) -eq 0 | } | ForEach-Object { | C
opy-Item -Path $_.FullName -Destination $Target -WhatIf}
At line:1 char:34
+ $Source = "I:\rob day 22\*.dng" |$Target = "I:\stills\" | $Increment  ...
+                                  ~~~~~~~
Expressions are only allowed as the first element of a pipeline.
At line:1 char:59
+ ...  = "I:\rob day 22\*.dng" |$Target = "I:\stills\" | $Increment = 1440  ...
+                                                        ~~~~~~~~~~
Expressions are only allowed as the first element of a pipeline.
At line:1 char:139
+ ... Get-ChildItem -Path $Source -File -Recurse | Where-Object { | ($_.Bas ...
+                                                                 ~
An empty pipe element is not allowed.
At line:1 char:190
+ ... -Object { | ($_.BaseName.Split("_")[-1] % $Increment) -eq 0 | } | For ...
+                                                                  ~
An empty pipe element is not allowed.
At line:1 char:212
+ ... e.Split("_")[-1] % $Increment) -eq 0 | } | ForEach-Object { | Copy-It ...
+                                                                 ~
An empty pipe element is not allowed.
    + CategoryInfo          : ParserError: (:) [], ParentContainsErrorRecordException
    + FullyQualifiedErrorId : ExpressionsMustBeFirstInPipeline

PS C:\Users\user>

Two possibilities:
1. Click "Select all" under the code box, copy it into the clipboard, paste it into an open PS console, hit Enter; this will only display the files it would copy:

gci "I:\rob day 22\*.dng" -File -R | ? {!($_.BaseName.Split("_")[-1] % 1440)} | % {Write-Host $_.FullName}

Select allOpen in new window

2. Click "Select all" under the "fleshed out" script, copy and paste it into Notepad, change $Source, $Target, $Increment to your likings, save it for example as C:\Temp\whatever.ps1.
In a PS console, enter
C:\Temp\whatever.ps1
If you get an error message about unsigned scripts and the execution policy, enter
Set-ExecutionPolicy RemoteSigned -Force
and try again.

but I don't see the destination folder here for matching files?

gci "I:\rob day 22\*.dng" -File -R | ? {!($_.BaseName.Split("_")[-1] % 1440)} | % {Write-Host $_.FullName}

Sorry to be a pain, it's been years since I did any code writing, I'm now  a DP... it's healthier then programming, but  this code looks like magic to me now =)