Sander, yes that is the basic idea.
However, I have not succeeded yet to create this:
Rangesum(Field1. Field2, ..) as ....
I hoped I could do this with concat, a variable and a loop but that generates only 1 field inside the concat, not 43 to 48 fields.
for a = 7 to $(number of fields in qvd)
let variable_name = concat($(qvd_fieldname)_$a), ',');
I'm stuck in generating a comma separated list.