Dear VBA-ers....

I'm struckling with an excel formula which counts unique values based on criteria in 2 other columns. The calculation of the formula works, but it takes a veeeeeeeeery long time, so perhaps a VBA code can do it faster.

Column.A exist of several location names.
Column.B exist of names which are related tot the location names in A.
Columnm.C exist of WeekNr's

In Column.D I need to count how many unique values in Column.A are related to the person in column.B in the same week in Column.C


Column.A Column.B Column.C Column.D
aa piet 3 3
aa piet 3 3
bb piet 3 3
cc piet 3 3

dd piet 4 1

dd kees 4 2
ee kees 4 2

ee klaas 4 1
ee klaas 4 1

ee klaas 5 2
ff klaas 5 2

So... if somebody can help me out :)

regards, Johan