The best way to handle this is , you need to build the complete logic in the Qlikview .
Qlikview will provide you the option to identify the whether the 1 st day of the month is Monday or not and based on this set a flag , so based on this you could build the data in the tables and NPrinting use this flag to run the report ...we have the condition feature in NPrinting that will run the report only if the condition is meet .