1. No guarantee but I just tested this old hack that was prevented in 1.7.3 by the developer after it was posted on the forum but seems to work again in 1.7.7.
Create a folder in the root of the drive or partition that XAMPP is installed on, for example in a default installation C:\usr
Next open the perl folder in XAMPP and copy by dragging with the Ctrl key pressed the 3 folders from the perl folder into the usr folder you just created.
Start Apache and MySQL and try one of your scripts with the #!/usr/bin/perl line and see if it works.
For example I changed the shebang in 2 files in the \xampp\cgi-bin folder, perltest.cgi and printenv.pl to #!/usr/bin/perl and then ran:http://localhost/cgi-bin/perltest.cgi
with a success with both files.
I then copied those 2 files to the htdocs folder and repeated the above test omitting the cgi-bin like so:http://localhost/printenv.pl
and once again both scripts worked fine.
Remember though that when you upgrade or install a later version of XAMPP that you would need to follow the above drag and drop folder procedure to update the perl files in the C:\usr folder.
2. In the C:\xampp\perl\bin folder and in the now C:\usr\bin folder is a ppm.bat file and a ppm.pl script which is most likely the equivalent but all I see is an error when I run either of these in the C:\xampp\perl\bin folder or in the C:\usr\bin folder, you may have more luck as I have run out of test time.
These 2 posts may help:viewtopic.php?f=16&t=48111viewtopic.php?f=16&t=49048
The latter outlines the errors that I get in 1.7.7 which still appear but that may be because perl in XAMPP may not be the Active Perl release and what is becoming more prevalent is the OP in this topic did not return to let us know if he found a solution for the one offered by JonB.