Android Custom Incoming Call Screen

I need an android app that will add some extra text to the incoming call screen. We use a VOIP phone system that will call forward phone numbers to our cell phones but when this happens the phone number that shows on the cell phone is the office number. So what I need is an app that when it receives a call from the office it checks our webserver and display the call forwarded number as well. The webservice is not part of this program, this app just needs to call a URL so we will need a settings screen were we can enter the "office" number and the extension then when we get a call from that "office" number you will have to make a call to [login to view URL] and it will return another phone number, I need that phone number displayed somewhere on the incoming call screen. Thanks and good luck