Manipulating Q931 call data fields * v1.8

I trying to get Asterisk to add the information elements Calling party subaddress and Called party subaddress into the Q931 setup message.

I’ve tried many of the combinations of using the functions CALLERID, CONNECTEDLINE and REDIRECTING without any success.

I have managed to get the Called party subaddress information element using the method
exten => 1000,n,Dial(SIP/1000[:called_subaddr],20)

Is there anyway of adding the Calling party subaddress ?

TIA.