So not sure exactly how you have it but I would loop though each day starting with PODate and check to see if a holiday or Weekend and if so, add 1 to your counter. Maybe something like:
vPOStartDate = Me.PODate
vCnt = 1
For i = vCnt to 5If Weekday(vPOStartDate) = 1 or Weekday(vPOStartDate) = 7 or Not Isnull(DLookup("[HolidayDate]", "tblHoliday", "[HolidayDate] = # & Me.vPOStartDate & #") then
vCnt = vCnt '(if the date is a holiday or weekend, then the counter stays the same)
Else
vCnt = vCnt + 1 '(if the date is not a holiday or weekend, then add 1 to counter)
End If
vPOStartDate = DateAdd(day,1,vPOStartDate) '(You are adding 1 day each time until your vCnt reaches 5)
Next i
Me.POStartDate = DateAdd(d, vCnt, PODate) '(if you had a Weekend in the 5 day span, then vCnt would be 7)
Not sure syntax is 100% on the Dlookup part.