Your running circles around yourself here.
dont mess with the SQM.
CDF is already in the game, no mod needed.
If you do have a mod for CDF then you need to find the script in the mission folder itself and change the classnames so that the mission uses those units and vehicles and whatever else.
The script adds the units not the SQM, the SQM is the result of whats put down in the editor,
It could be possible to change the classnames in the SQM but its not going to work becasue the scripts are hard coded to load a specific classname for the mission,
so change the scripts, then you end up changing the SQM.
You could as I have pointed out is add your units and vehicles and stuff to the mission and play with those.
Take the playable units you choosewhen you start the mission and then replace those with the units from the CDF mod your using,
but transfer the codes from the original units to the new units before you delete them.
For the vehicles, just add your vehicles, planes, and or choppers you want, and just transfer the respawn codes from the init lines in them,
to me that would be the easiest way.