Hi Dan,
group account is not available in FAGLFLEXT by default.
In BCS I use the follwoing way:
What you can do to obtain the group account number during load from data stream is the following
You may add an attribute (e.g. group account) to the BW infoobject for account. And in the load from datastream method you derive the target field FS item from this attribute 'group account'(of the source field 'account').
It could be also an option in EC-CS, but you have to go throught BW and back to EC-CS via load from data stream.
It's no a ideal solution - mayba it helps.
Best regards
thomas