StarSiege?

Not really,

although they both use the same base Siege engine mechanism for skill resolution there are really very different animals.

At one point I was considering creating an extension to the C&C ruleset to runs starsiege, but in the end I decided that the differences were so great that I would really have to built an entirely new ruleset.

Its still on my list of things to do if I get time, but the time has not yet come...

Maybe I will look at it again after the release of the C&C v2.2 (or whatever it ends up being called).