Hi there.
First of all: don't post the same question many times in many different forums just because you don't get an answer immediately. We'll use this topic for discussing the problem now.
As to the question: normally just adding the second mod after the first one's in the command line ;@Invasion44 or whatever the folder name should work - I do know however that Libmod quite liberally hides most things not used in the actual mod. Also Libmod and Invasion 44 use entirely different values for their units and armor - so it's not likely to be a fair fight even if you do manage to get them to work together.
That's all the help I can give you, sorry.
Wolfrug out.