If the module isa Exporter- or, at least, if it behaves like most CPAN modules I'm familiar with- you can usually find the version at the command line by:
in reply to Checking for an installed Module's version.
$ perl -MModule::Name -e 'print $Module::Name::VERSION,"\n"';
Of course, if you're using ExtUtils::MakeMaker to write the make file, the WriteMakefile method has a parameter called 'PREREQ_PM' that lets you specify the modules you need as well as their minimum versions.
Hope this helps!
-><- -><- -><- -><- -><-
All things are Perfect
To every last Flaw
And bound in accord
With Eris's Law
- HBT; The Book of Advice, 1:7