From CLI:
    -- Executing Dial("SIP/213-081a65a8", "SIP/299|20|t") in new stack
    -- Called 299
    -- SIP/299-081923c8 is ringing
    -- SIP/299-081923c8 is ringing
    -- SIP/299-081923c8 is ringing
    -- SIP/299-081923c8 is ringing
    -- SIP/299-081923c8 is ringing
    -- Executing NoOp("SIP/207-081a91c8", "Trying 299@desk-phones") in new stack
    -- Executing Pickup("SIP/207-081a91c8", "299@desk-phones") in new stack
  == Spawn extension (internal, **299, 2) exited non-zero on 'SIP/207-081a91c8'
    -- SIP/299-081923c8 is ringing
    -- SIP/299-081923c8 is ringing
    -- SIP/299-081923c8 is ringing
    -- SIP/299-081923c8 is ringing



From extensions.conf
        exten => _**2XX,1,NoOp(Trying ${EXTEN:2}@desk-phones)
        exten => _**2XX,n,Pickup(${EXTEN:2}@desk-phones)