Extract filename from filepath

Hi,

I have a batch file in my sendto folder (it's called batch.bat) that's called with a parameter by right-clicking on any file>sendto>batch. Note that the parameter sent is the "filepath" not "filename". The batch looks like this:

copy %1 c:\windows
(which translates to)
copy c:\filename.exe c:\windows

if I right-click on a file named filename.exe>sendto>batch
The parameter %1 passed is "c:\filename.exe". Now the next line involves renaming the file which is where I have a problem.
rename %1 filename.bak will not work because this will rename c:\filename.txt to backup.bak while my intention is to rename c:\windows\filename.txt to backup.bak.

How do I achieve this? Obviously by extracting the filename and putting it in a variablelike this:

copy %1 c:\windows
;define %filename%
rename c:\windows\%filename% backup.bak

The problem is I don't know how to extract the filename. I would greatly appreciate any help.

Thanks in advance,

ram_einstein