WHSCON or SHPCON : how to transfer the picking request number ?


I want to pick & pack an outbound delivery using the idoc WHSCON.

Using the WE19 transaction I have simulated an inbound idoc with qualif. PIC in segment E1EDL18. It works fine.

My problem is that a new picking request is created for the delivery. It has the same number as the delivery. Because of this, the picking quantity is added to the delivery quantity.

So my question is quite simple : in order WHSCON (or SHPCON), in which segment and field must i put the picking request number ?

Subsidiary question : Is it a difference between messages SHPCON and SHPCON ?