You'll need to specify how you define the week number within a month?
Is week 1 always 1st to 7th?
Presumably the Monday of week 5 can actually fall in the next month?

Perhaps:
=DATE(C2,A2,B2*7-6)+MOD(7-WEEKDAY(DATE(C2,A2,B2*7-6),3),7)
--
David Biddulph

Pete Hay wrote:
What is the easiest way to convert three values - Month, Week, Year
to a date? Date would be the Monday of the week specified.
Pete