When you install Perl, it will edit %INC so you don't need to do that for people. It used to be, and likely still is, that when you install it that a couple of important dlls are put in your system folder. Look for PerlCRT.dll (not sure if there is another, and this may have changed in recent releases - I haven't seriously used Windows for years). Copy those to the bin directory on the shared drive.

Now all that you need to do is edit the PATH, and you're done. In fact you should be able to just run pl2bat on your Perl scripts, and edit the result to call Perl explicitly in the right location.

Good luck!