getting DID from invite

[custom-get-did-from-sip]
exten => s,1,Noop(Fixing DID using information from SIP TO header)
exten => s,n,Set(pseudodid=${SIP_HEADER(To)})
exten => s,n,Set(pseudodid=${CUT(pseudodid,@,1)})
exten => s,n,Set(pseudodid=${CUT(pseudodid,:,2)})
exten => s,n,Set(pseudodid=${CUT(pseudodid,+,2)})
exten => s,n,Set(isuk=${REGEX("^44.*" ${pseudodid})})
exten => s,n,Set(pseudodid=${IF(${isuk}?0${pseudodid:2}:${pseudodid}))
exten => s,n,Set(pseudocid=${CALLERID(num)})
exten => s,n,Set(pseudocid=${CUT(pseudocid,+,2)})
exten => s,n,Set(isuk=${REGEX("^44.*" ${pseudocid})})
exten => s,n,Set(pseudocid=${IF(${isuk}?0${pseudocid:2}:${pseudocid}))
exten => s,n,Set(CALLERID(num)=${pseudocid})
exten => s,n,Set(CALLERID(name)=${pseudocid})
exten => s,n,Goto(from-trunk,${pseudodid},1)