Override Button

[Dayton_Tech]

We have a hosted phone system and the button programming is done within our online portal. We have a door release on our main door that can be activated by an HTTP command from our internal network only. I log into the phone(s) website and set a button to XML browser with the value being the HTTP command to release the door on a timer. This works great until we lose power and the phones reboot, all of our hosted phone system buttons are restored but the button I programmed manually through the web interface is gone. Our provider doesn't offer XML browser as a programmable button within our online portal.

I would like to program an override (which our provider allows) that will allow me to program a button to use XML browser and the HTTP command needed. However I don't know how to write the override and I'm looking for assistance.

Is this possible and could anyone assist?