Forward LDN to Overflow Key Line after X number of rings

[RossIV]

I am working on a Mitel SX-200 LW17 with Superset 4025s and 4150s. Our main front desk extensions are 4150s and all other admins have 4025s. All of the 4025s have three Key Lines that are Overflow 1-3 (3501-3503 respectively). Before my time, I was told that those keys rang after three rings of the main phones. This is no longer the case. Is it possible for me to have the LDN forward to these Key Lines after 3 rings?
Thanks!

[johnp]

Yes, read about feature attendant calls fowarded on no answer