Remove number prefix

I work from home, and I want to send my work related calls to a different SIP gateway to my normal one (so it can be billed to me separately).

If I prefix all work related calls with a 9, how do I remove that 9, before its passed to the SIP gateway?

exten => _0.,1,Dial(SIP/${EXTEN}@sip-gateway)
exten => _9.,1,Dial(SIP/9|${EXTEN}@sip-gateway-work)

exten => _0.,1,Dial(SIP/${EXTEN}@sip-gateway)
exten => _9.,1,Dial(SIP/9|${EXTEN:1}@sip-gateway-work)

sorry:

exten => _0.,1,Dial(SIP/${EXTEN}@sip-gateway)
exten => _9.,1,Dial(SIP/${EXTEN:1}@sip-gateway-work)

Thank you yusuf, that works. :smile: