One suggestion... if you store the variables you need in a big hash you could do things like iterate over the hash to get all the variables you need. You could then use something like Data::Dumper to serialize the hash and pass it off to the second CGI.

Ideally, however, I would suggest making the functionality of the second cgi into a library, then you could just call the code from that one directly without executing another script and futzing the data around. If you need them to run in parallel you could use fork.

Modulizing the second one would ideally be the way to go... otherwise you either have to serialize the data for the second, or pass it all in as parameters... very ugly for large lists.