Ring Group in Ring Group

I have one ring group with internal extensions.

I have another ring group with mobiles.

I would like incoming calls to first ring the internal numbers and then internal + mobiles (memory hunt).

As it appears you cannot have a RG in a RG, does anyone have a workaround?

I do not want to go through individual extensions, as it will take too long to get to the mobiles and I do not want to delay the caller in speaker to us.

You can have a ring group in a ring group. Check the mouse over help, all non-extension numbers listed in a ring group must have a # suffix. Be prepared for messy CDR entries.