RT-N66U Merlin and USB cellular modem

[Gordon1M]

I am trying to find a way to provide a backup Internet service using a USB cellular modem on my RT-N66U Merlin router. The existing Merlin USB modem options only show Rogers (in Canada) as the available service. However the Rocketstick modem is no longer available from Rogers. Bell Mobility offers a stick modem (Novatel U679) but the Merlin firmware doesn't seem to directly support anything but Rogers. Maybe it is possible to insert the appropriate parameters for Bell. Has anyone been able to use a stick modem from a Canadian cellular ISP, other than Rogers, which works with the N66U.

Thank you
Gordon