[cisco-voip] MGCP Gateway Calling Number Manipulation

[gweissenfels at gmx.de]

Hello Team,

following topology:

PSTN------SiemensPBX---(Q-SIG)---MGCP-GW------CUCM_6.1.1

If a call comes in from the PSTN to the CUCM world via the QSIG-Trunk, the calling number is displayed on the IP Phone like this 32xxxxxxxxxxxx for a call from belgium for example. It is not possible to call this number back, because the leading zeros are missing.  The calling number should look like this: 00032xxxxxxxxxxx. One 0 is needed to get an outside dialtone. 
With H.323 i would do a digit manipulation on the gateway and prefix 000 to the incoming calling national / international number.
Is there a way to do this with MGCP via the CUCM administration? 

Any ideas?

Thanks in advance!

Gregor