I am testing a new trunk in the dialplan by routing a single number through it. All the other numbers use the existing trunk and will be switched over later. This means I match the whole number and use it in the dial plan. However when I use $0 on its on in the dial string it works okay, but when I prefix it, eg 240$0 the $0 is not translated to the dialled number and is sent literally to the provider with the obvious results.

    <!-- route 1234 numbers through trunkxxx ->
    <condition field="destination_number"  break="on-true"
          expression="^1234567890$">
          <action application="bridge" data="sofia/gateway/trunkxxx/240$0"/>
    </condition>