Aside from the difficulty in porting the C to the Palm OS due to the kludged or complete abscence of STL
(I really mean standard library--Sorry) support, the changes you would have to make to the actual design of Perl are rather significant. At best, you would end up with a "Perl-like" program.
First, the Palm OS doesn't have STDIN, STDOUT or STDERR. Now, the MacPerl people overcame that rather creatively, but since the Palm OS doesn't have a filesystem (at least not in the traditional sense), not even the most basic functionality exists. What you would have to do, I suppose, is write some sort of complicated system wherein you created a large resource database and then wrote an interface to it that emulated traditional filesystem calls.
In the end, I don't understand how useful this would be. If you need a certain Perl-like functionality in a program, you would be better off trying to simply implement that functionality in a traditional Palm application.