Actually my noobness got me good.
Was thinking "ME7 fr" would had been some other ecu which would had had allready a XDF made for it, which could had been modified to suit my needs.
WRONG, it is a multi hundred page document in german which apparently hides inside it the information for making the XDF file.
Seems daunting,but i guess i will have to dive into it. Hope the car is not a pile of rust when im finished