Ok - found it out. Perhaps this might help also other NPrinting users:
A variable for the Previous Quarter needs to be defined in QV, in this cased I named it vPrevQuarter:
'=((CALENDER.DATE>='& chr(39) & QuarterStart(num(QuarterStart(today()))-1) & chr(39) &') and (CALENDER.DATE<=' & chr(39) & QuarterEnd(num(QuarterStart(today()))-1) & chr(39) & '))'
And then I could call the variable with NPrinting :
Attention: "Evaluate" needs to be ticked.