Given a Year and a Week number, how can I get the first date in that week, in .Net?

Question

Possible Duplicate:
Calculate date from week number

I have a Year and a Week number within that year (I got these by doing "YEAR(Date) AS Year, DATEPART(WEEK, Date) AS Week" in SQL), and I'd like to know the date of the first day of that week.

Actually, ANY day in that week is good enough, I just think the first one is the most likely to be around.

Esentially, what I want to do is the inverse of the Calendar.GetWeekOfYear function.

Any ideas how to do this in a less ugly way that starting on 1/1 and looping over each day querying for the week number until I find it?

Thanks! Daniel