I am using the VBA DatePart Function as a function in Excel:

Function DatePartFunction(qualfier As String, rng As Date)
DatePartFunction = DatePart(qualfier, rng)
End Function

According to the Help resources, the function takes the following arguments:
DatePart(interval, date[,firstdayofweek[, firstweekofyear]])

How do I incoporate the firstdayofweek and firstweekofyear arguments.  For
example in A1 I have the following date: 24/03/2006.  Then in B1 I have the
following formula: =DatePartFunction("ww",$A$1) - See list below.  The result
in B1 is 6.  I am assuming that as 24/03/2006 is a Friday that the 6 must
mean that the first day of the week is assumed to be Sunday.  I want to set
the first day of the week to Monday so that the result of the function is 5.  
How do I do this in code/Excel?  Thanks

yyyy Year
q Quarter
m Month
y Day of year
d Day
w Weekday
ww Week
h Hour
n Minute
s Second