Correcting callerid


we have * connected to a isdn pri

the callerid presented drops the leading 0 from the callers tel number.

is there an easy way of adding a number (eg 0) to the front of the callerid?

obviously we would only want to do this on the pri trunk?

I know that we can add numbers to any number called (eg if we tried to return the call we could add 9 for an outside line, then 0 to the number via the dialplans, but I would really like to add the 0 as the call comes in, so that on amp the number is displayed correctly as well :question: