Your REGEX is not working. You should use mine. Also, your proposed solution will have the call go through the dialplan twice instead of once before it reached the bridge command
You posted your question in the FS PBX subforum, not FusionPBX. It's important to note that these are two distinct products. FS PBX was forked from FusionPBX and redesigned for everyday use, with a new admin portal. Overall, it's a more mature product for daily PBX management. More information is available at www.fspbx.com.
Since Dialplan is managed by Freeswitch, my previous answer still applies to both systems. However, I cannot respond to your last question specifically about FusionPBX.