Get Monday from date field in Excel

Hi, could use some help.

I have a spreadsheet with a list of items and a date in column 2.

I need to look at the date and determine the week that it falls under then place the date for Monday into Column 1.

I would appreciate any ideas on how to tackle this. Inserting an excel formula using VBA might be an option because I would need to input the column and row index into the formula in a for each process.

How about the following expression

aMondayDate = aDate.AddDays(-aDate.DayOfWeek+1)

Cheers