Complete number substitution - dialplan

Hi,

Apologies if this is a FAQ but I couldn’t easily find the answer.

I was expecting to be able to do number substitution in dial patterns, e.g.

08701117200|08000490049

to replace the 0870 number with a freephone number in my outbound route. However this just results in: SIP/2.0 484 Address Incomplete

In my log I see: VERBOSE[5345] logger.c: Looking for 08701117200 in from-internal

So how should I do this? Ultimately, it would be great to be able to look up the alternative on saynoto0870.com and do it automatically Wink

Thanks,
Chris.