forward hunt group to external number on busy

[mhumphries]

i have a situation where i need to forward on busy a hunt group to an external number. 
i have ext 3197 which contains ext 3400, 3401, 3402, 3403
i have a separate external hotdesk (7400) setup with an external number of 1234xxxxxx

i have the CoS set up on this and i beleive that it should work, however when i dial the number directly i get out of service. 

i have the hunt group number in call rerouting set to first alternative 336
336 points to 7400
my goal is to have the calls come into the hunt group and if these are all busy it will forward the calls to 1234xxxxxxx.
if there is a better way i am all ears, or if i am missing something in my config i am ready to adjust.  any help is much appreciated.

[VinceWhirlwind]

I don't know about a Hunt Group, because I always use Ring Groups.
Here is the test setup I just did to demonstrate how this works:
 
System Speed Call 1003 --> 00212341234
Ring Group 1001, member 1002, overflow to 1003
member 1002 set to DND
 
I ring 1001, the call rings on 0212341234

[mhumphries]

so you let me down the right path.  i have the hunt group set as terminal. setup a system speed call and then added it as the last member of the group.  that worked as intended.