there is an 'append object' command you specify the animation file to append, the object to append it to, and the start frame of the appended animation in the objects frame set.
so if you have objecta with frames 0-40 for walk and objectb with frames 0-20 for jump you can
load object "objecta.x",1
append object "objectb.x", 1, 41
so that the jump will take frames 41-61 in objecta
it looks like you are using the gdk so the structure will be different but I'm sure the command is still there.
really though any sort of code questions will be better off asked in the dbpro/dark gdk sections of the forum. the 3d chat is more for artists and the production of media than it is in using said media in code.