Honestly that sounds a little difficult! Why not while on the call just turn off the Bluetooth then after call connects turn it back on. Now your connected to your call.
And I have posted about this awhile back when this Rom first stated. It's the easier way for a work around for Bluetooth to work for calls. And even grabbed a Bluetooth widget to make it a lil faster. After call pop back to home screen!
I tried this work-around for connecting to my car's bluetooth, and here is my experience:
The phone connected immediately with the car BT. I transferred the contacts, and the pairing was lost. I re-paired the connection, and the connection was stable.
I made a call, turned off the BT, and turned it back on. However, the connection was not automatically paired. I went and re-connected on the car's end, and then I was able to talk through car's BT. So, it does work, just needs couple of more steps.
Also, the config did not stay, and when I needed to make another call, I had to go through the hoop once more. Tried it again, and again had to go through the whole thing of disconnecting the BT on the phone, reconnecting the BT on the phone and reconnecting the BT on the car's end. Which means this work-around needs to be done on every call.
No doubt this is just a temporary fix, I will be so happy when there is a permanent fix.