How to change Queue agent login BLF


I have a freepbx distro running and i have a few tiptel iphones connected.
Everything is working fine.
For the incoming route if first go through a call flow which if active sends the call to a queue.
All the phone login on the queue by pressing the BLF.
But if your logged in the button turns red and i want to change the BLF to turn green.
But without changing blf status on the phone themselfs because i also have for the call flow a BLF and that does turn Green if the call flow is active.

Hope i explained it well.