I have set up a IP-PBX with a GSM gateway. This lets me call into my PBX. At this point I reach a IVR. One option lets me forward a call over VOIP by sending a destination.
To automate this I decorated the destination with the gateway number and pauses. As described about.com.
So I end up having to enter a number for each of my contacts like so:
Anybody knows an app who let me do that for Android?