Problem with caller ID identification after adding prefix

Hi,

I used the following settings to add a "0" to the incoming caller id, so I can callback missed calls directly from the phone.

[from-pstn-custom]
exten => _X!,1,Set(CALLERID(num)=0${CALLERID(num)})

This works pretty well, but causes some headaches with HUD, because HUD is now unable to identify incoming callers because of the added "0". Is there a way to work around this? I think it is not uncommon that a prefix needs to be added on incoming calls.

Regards,

Jens