Hope this can be done. script that have timer. that one extension has specific time in a call. the script automatic

Hope this can be done. script that have timer. that one extension has specific time in a call. the script automatic send the call in hold and after x secs return the call to the original extension.

the scenario

a gsm gateway that have free call time for first 5 minutes. so the gsm gateway is in extension 1000. so one call then it routes to gsm gateway but at minute 4.30 the call goes to a park slots (hold) then it returns so the gsm gateway extension can have unlimited time with this

I can achieve this manualy
when 5 minutes is reaching. i sent the call on hold for 15 sec then I have configured that call in hold return to the original extension after that 15 minutes
but it have to see the cell each time the 5 minutes arrives. so Would be nice to do automatic with a script or something.
if one here can drive me in the right direction of doing this. that would be great appreciate
thanks so much