How to dynamically determine Receivers within BPM

Question

I’m trying to design a way to determine my receivers within my BPM process during runtime.   My Scenario is as follows:
SAP IDOC
    V
  XI
             XI uses JAVA Mapping MT1 to determine vendors and if customer receives PIDX
                         JAVA Mapping MT2 to creates the PIDX output file if required
  V
SENDs to required Vendor (PIDX if required otherwise email)
My problem is how to dynamically determine the appropriate receiving vendor for my PIDX.
I can not use the condition editor on the standard Receiver Determination because the output message (PIDX) doesn't have specific enough information to determine the vendor.
Other than the customer number there are no other values and we don't want to use customer number because each vendor can have multiple customer numbers (hundreds).
I've tried various attempts but none seem to work.  This could also be because I have limited knowledge of BPMs and this is my first complex development.  Below are the different attempts I've made at dynamically determining the receiver.  Any input would be appreciated.
Receiver Scenario 1 
  I developed an interface mapping with MT1 as input and the SAP Receiver Determination as output.  The problem is for me to use this, the interface mapping had to reference the PIDX output (MT2 instead of MT1) which has no data that I can use to determine the receiver.
Receiver Scenario 2
I added a receiver step right before my send step and used the receiver list.  This appears to send the PIDX to everyone in the list and there is no way to evaluate or eliminate a name from the list. 
Receiver Scenario 3
I created a context object in the Integration Builder and assigned it to a field in MT1.  I then added a switch step with a branch for each vendor.  Within each specific branch there is a Send step that has the context object name I created in the "Send Context" field.  However, on the configuration side I’m unable to access the context object which I created on the design side.  Whenever I open the condition editor and select the radiobutton for "Context Object" the list  does not include the context object I created in the Integration Builder.

Answer 1

Hi,
Try using the enhaced receiver determination concept.
Maybe based on certain field values you can write a UDF which calculates the receiver.
Try this Blog out
Link : [
http://help.sap.com/saphelp_nw70/helpdata/en/43/a5f2066340332de10000000a11466f/frameset.htm]
Regards,
Abhishek
Award if helpful.