TRADACOMS document type not showing all fields on the Trading Networks console

I receive EDI orders from a number of customers in a TRADACOMS 6 format, I can currently process these fine from Trading Networks through to our ESB. However, we are now looking at taking on a new customer that uses the same format on the inbound messages but requires a different set of processing to take place. I’d like to identify these as early as possible in my processing. I can’t do this at the envelope level as there is nothing here I can use to distinguish between the 2 customer groups - the data I can use is contained in the message header segment (sample below)

MHD=1+ORDHDR:6’TYP=0460’SDT=:1111’CDT=1234556789+ACME PLC’FIL=1234+1+140704’MTR=6’

I need to be able to set up my processing rule in Trading Networks based on the value in the SDT field (in this case 1111) - however I can’t see this segment at all in the document type on the Trading Networks console. In Trading Networks I can only see the message fr from the second MHD

Complete sample message:

STX=ANA:1+1234567890+1234567890+140704:030508+1234567890+ +ORDFIN’
MHD=1+ORDHDR:6’TYP=0460’SDT=:1111’CDT=123456789+ACME PLC’FIL=1234+1+140704’MTR=6’
MHD=2+ORDERS:8’CLO=:ZZ+DEPOT1’ORD=1234567890::140704’DIN=140707+140708++AM’DNA=1++237:GBR’OLD=1+9999999999999++:00123456+8:0+10+175100+++PRODUCT A’DNB=1+1++043:00010:109:A11’OTR=1’MTR=9’

On the Trading Networks console in the document type for TRADACOMS 6 ORDHDR I only have the fields from MHD=2 onwards for the order - I cannot see any of the MHD=1 fields - and the SDT field is the one I need to use to identify the message.

Once the message has made it onto the IS I can see all the segments I need - but ideally I want to do my routing in Trading Networks rather than having to create a service to do my routing (after all that’s exactly what the processing rules are for!). Any help appreciated.