Yes, use perl 5.12.
You'll also need to edit the source code to use the proper libraries. Find in files for perl510, and change both lines it lists to perl512.
These are the lines you should see after your search:
Code:
C:\EQEmu\ServerCode\trunk\EQEmuServer\world\EQWParser.cpp(35):#pragma comment(lib, "perl510.lib")
C:\EQEmu\ServerCode\trunk\EQEmuServer\zone\embperl.cpp(26):#pragma comment(lib, "perl510.lib")