[asterisk-users] Adding/Removing Prefixes

[Scott Pinhorne]

Hi All

When a user wishes to 'break out' they prefix there call with a 9.
I know how to remove the 9 and then dial the remaining number and this 
is all working fine.

I now need to remove the 9 but then prefix another number onto the phone 
number before dialing now but am unsure how to do this is the dialplan.

Would someone be able to point me in the right direction or provide an 
example diaplan that does this?

Many Thanks in Advance
SP