moving multi mesh rig to UDK

First of all I must admit I am a 2 week old noob to blender and 3D modelling but I think I am picking up fast.
I am looking for a way to export my tank model into UDK as a playable character.
The trouble I face is my tank is made up of multiple objects (hull, turret and gun etc.) which move independently and the PSK file extension export doesn’t allow me to have multiple objects in my mesh.

Is there a way for me to modify my tank rig so that I can join all the component objects after placing them in vertex groups and still control the components using vertex groups bound to bones in my armature?
I was able to place the components of the tank in vertex groups but I am at a loss on how to control the individual vertext groups with my bones.
Much Thanks for your help!

to join the selected objects select them all and press Ctrl+J to join the meshes I don’t think it will mess with your vertex groups either.