[Resolved] Dial Plan Help

Can any one help me in implementing changes in extensions.conf. I am using asterisk as SIP server bw two peers and routing on basis of prefixes.
want to add 39 at start of 877 and pass it on to peer XXX
Where to apply chages?

exten => _877.,1,Dial(SIP/${EXTEN}@XXXX)

exten => _877.,1,Dial(SIP/39${EXTEN}@XXXX)

Thanks it worked. :smile: