Subtracting Hold Days from Network Days Formula

Hi,

The formula below works out product ontime delivery by calculating the difference between two stored dates (start date) Q and (shipment date) R, this formula excludes weekends and public holidays. it then returns a 1 or 0 value depending on whether it is within a 4 day on time delivery range.

However, i now have a new field which is 'time on hold'. I want to subtract the 'time on hold', which is recorded in number of days, from the shipment date. however, i want the days it takes off the shipment date not to include weekends and holidays.

=IF(NETWORKDAYS(Q14302,R14302,HolidayRange)-1<=4,1,0)


Thanks in advance,

David