Insert the calendar control on your worksheet:
1. select Insert/Object from the menu.
2. select the calendar object from the list of object.
Open the VB editor:
1. select Tools/Macro/Visual Basic Editor from the menu.
2. double-click the worksheet named in the list to the left.
3. select the calenar object from the drop-down list (usually called Calendar1, unless you renamed it).
4. select the Click event from the drop down list on the right.
5. write the code you want to execute, for example:
'This will write the date clicked on to the cell in Row 7, Column 7.
me.cells(7,7)=me.calendar1.value