Hello! I am just learning Perl myself, but I recently ran across a module that might be a good fit: Damian Conway's Inline::Files. It generalizes the __DATA__ construct and allows to you have an arbitrary number of "files" inline with your code -- and if the user has write permission to the program, these datahandles can be opened for read/write access too. So you could create an __OPTIONS__ section with default values, and replace them as desired. Check Damian's diary entry for May 26th
for more info.