WWW::Scripter::Plugin::JavaScript is still relatively new, having been released Oct. 25, 2009. This is one of those instances where you'll need to prove it out and maybe post the results with any questions here.

I haven't had any need to use it, so I don't have an example for you; although there is one "little" bug that I noticed. Per the documentation:

There is currently no system in place for preventing pages from different sites from communicating with each other.