RingGroups & Queue's with Other (Custom) Device

FreePBX 2.5.2.2 with Asterisk version 1.4.26.1.

Trying to get a ring group to include custom extensions. I’ve an extension 451 that is set up as a Other(Custom)Device in the extensions module and it’s got the following in the “dial” field:

SIP/‘mytrunk’/‘mycell’

I’ve put extension 451 in the Ring group 601 and when I call the ring group 601 the caller hear’s ringback but I never get a call delivered to ‘mycell’. If I dial the extension direct, the call is successfully delivered to ‘mycell’. I know in ring groups you can enter in the external Dial, but I really need to have the ring group & the Queue’s dial an extension instead of an external number.

Did you get it working?