You could build and install the same version of Perl on your system twice. Just when you run Configure to build and install your second version use --prefix=/some/where/else. Then install the module you want to test in both Perl's. Something like
in reply to Change package name on the fly?
Then in your test script just change the shebang.
$ /where/you/put/bin/perl -MCPAN shell
cpan> install NWCLARK/Foo-Bar-0.02.tar.gz
$ /some/where/else/bin/perl -MCPAN shell
cpan> install NWCLARK/Foo-Bar-0.01.tar.gz