Something

exten = *40,1,Answer
exten = *40,n,Wait(1)
exten = *40,n,Playback(cust-pro-call-fwd-busy)
exten = *40,n,Playback(please-enter-your&extension)
exten = *40,n,Read(fromext,then-press-pound)
exten = *40,n,Set(fromext=${IF($["${fromext}"=""]?${CALLERID(num)}:${fromext})})
exten = *40,n,vmauthenticate(${fromext})
exten = *40,n,Wait(1)
exten = *40,n,Set(LOOPCOUNT=0)
exten = *40,n(begin),Set(TIMEOUT(digit)=3)
exten = *40,n,Set(TIMEOUT(response)=10)
exten = *40,n(startread),Playback(ent-target-attendant)
exten = *40,n,Read(toext,then-press-pound)
exten = *40,n,GotoIf($["foo${toext}"="foo"]?startread)
exten = *40,n,Wait(1)
exten = *40,n,ChanIsAvail(SIP/${toext}&IAX2/${toext}&MGCP/${toext}&SKINNY/${toext})
exten = *40,n,GotoIF(${AVAILSTATUS}=""|?i,1)
exten = *40,n,Set(DB(CFB/${fromext})=${toext})
exten = *40,n,Playback(call-fwd-busy&for&extension)
exten = *40,n,SayDigits(${fromext})
exten = *40,n,Playback(is-set-to)
exten = *40,n,SayDigits(${toext})
exten = *40,n,Goto(hang,1)
exten = i,1,PlayBack(invalid&extension)
exten = i,n,Goto(loop,1)
exten = t,1,Goto(loop,1)
exten = loop,1,Set(LOOPCOUNT=$[${LOOPCOUNT} + 1])
exten = loop,n,GotoIf($[${LOOPCOUNT} > 2]?hang,1)
exten = loop,n,Goto(app-cpcfda,,begin)
exten = hang,1,Playback(vm-goodbye)
exten = hang,n,Macro(hangupcall)