How to fitt different skeletal matrix to another

Hello im using a script calld actorxImporter, it suits perfectly for importing models in 3ds max - mesh and skeleton, it also has an future to merge imported skeletal matrix onto existing, means if Bone names of skeleton that are in scene are same as bone names that get to be imported - it automaticaly merge them.
But problem is that, it works in a wrong way, i need it to be so that imported skeleton matrix - get shape from existing skeleton(that is in scene), but now it work's in reverse
existing skeleton get shape from skeleton that is importing, so final model get's wrong dimensions, is it possible to change it in the right way ? Im not so fammiliar with maxscript - could someone give me a little help, describing a bit what can be done - please ?