It would be theoretically possible but would require some fairly serious work. What I'd suggest is extract ALL the resources from the other client. Make a tool to add all the resources needed for a specific map into the conquer client.
Make sure that tool works to add the map. it WILL look funky.
Now edit the tool so that as it adds the sources it automaticly converts them so that they fit better with the conquer client (Batch convert the dds images so they are the right size, edit the other files to fit the new pics, if needed edit the dmap information to fit the new images)
That's all you'd really have to do. It wouldn't take THAT much work to be honest but it would be hella annoying to get working PERFECTLY. To get it working reasonably is easy but to make it seamlessly blend in with the conquer client would be... difficult.