Modify a Powershell script to relpace a character

I would like to modify the attached script so that when it sees 01-ABCDA, or 01ABCDB, 'and' if sees either 01230c, or 01232 in position 100, that it will change the last character from whatever 3 digits it sees at the end of those lines, to a ,008.

No other functions in the script are needed, so I am sure many of the lines will have to be removed.....

$inFolder = '\\saved\data'
$outSuffix = '_rev'


$referenceCount = 0
$row = 0
Get-ChildItem -Path $inFolder -Filter *.csv | Where-Object {$_.BaseName -notmatch "$($outSuffix)\Z"} | ForEach-Object {
	$outFile = Join-Path -Path $_.DirectoryName -ChildPath "$($_.BaseName)$($outSuffix)$($_.Extension)"
	$saveFile = $false
	Write-Host "Processing '$($_.Name)' ..."
	$content = Get-Content -Path $_.FullName | ForEach-Object {
		$fieldChanged = $false
		$row++
		$fields = $_.Split(',')
		If ($referenceCount -eq 0) {$referenceCount = $fields.Count}
		If ($fields.Count -ne $referenceCount) {
		   Throw "Field count in line $($row) is incorrect (is: $($fields.Count), expected: $($referenceCount))!"
		}
		$fields = $fields + ''
		$old3 = $fields[3]
		If ($addLastField.Keys -contains $fields[3]) {
			$fields[-1] = $addLastField[$fields[3]]
			$fieldChanged = $true
		}

		If ($fieldChanged) {
			Write-Host "    line $($row): $($old3) [$($fields[26])]) --> $($fields[3]); last: $($fields[-1])"
			$saveFile = $true
		}
		$fields -join ','
	}
	If ($saveFile) {
		$content | Set-Content -Path $outFile
		Write-Host "Changes written to $($outFile)."
	} Else {
		Write-Host "No changes found."
	}
}

This is the input script in a .csv file.

5,A,01234,01-ABCDA,Y,1251/2,1772345,,20181003,20181107,20181114,,1234567890000,COMP ACCOUNTS PAYABLE,123 ROAD WAY,,TREEWAY,FL,01234-5678,,,,1234564870004,Somewhere Warehouse,200 Treeview Court NW,,Everywhere,GA,12345-1234,,,018-441-5522,41245,ABCORPBC,,USD,N,,,,,,,,,,N,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,00987894561230,01230c,152324,STEEL,,,,123.00,US,0.00,US,0.00,US,10.5000,0.0000,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,101
5,A,01234,01-ABCDB,Y,1251/2,1772345,,20181003,20181107,20181114,,1234567890000,COMP ACCOUNTS PAYABLE,123 ROAR WAY,,TREEWAY,FL,01234-5678,,,,1234564870004,Somewhere Warehouse,200 Treeview Court NW,,Everywhere,GA,12345-1234,,,018-441-5522,41245,ABCORPBC,,USD,N,,,,,,,,,,N,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,00987894561560,01232,152345,WOOD,,,,789.00,US,0.00,US,0.00,US,10.5100,0.0000,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,102
5,A,01234,67891,Y,1253/2,1775478,,20181003,20181107,20181114,,1234567890000,OTHERCOMP ACCOUNTS PAYABLE,123 ROAD WAY,,FOREST,TX,01234-5678,,,,1234564870004,Another Warehouse, 300 Apt View Court NW,Specific Place,TX,12345-5678,,,018-441-5522,41245,DEFORPBC,,USD,N,,,,,,,,,,N,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,00987894564560,00456,152322,CANVAS,,,,123.00,US,0.00,US,0.00,US,10.5200,0.0000,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,103
5,A,01234,55555,Y,1254/2,1771234,,20181003,20181107,20181114,,1234567890000,OTHEROTHERCOMP ACCOUNTS PAYABLE,123 ROAD WAY,,JUNGLE,GA,01234-9999,,,,1234564870004,BAnother Warehouse, 400 Sea View Court NW,AnotherSpecific Place,GA,12345-9999,,,018-441-5522,41245,GHIORPBC,,USD,N,,,,,,,,,,N,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,00987894564560,00456,152322,CANVAS,,,,123.00,US,0.00,US,0.00,US,10.5200,0.0000,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,104