Excel:How change the textbox format from text to date format?

Hi@all
I am using Excel 2007 (German Version) and hope someone can help me with the following:
I have created a user form with several input boxes. Two of these Boxes are TextBoxes that are used to get dates from a pic up calendar next to them. These dates are then transferred from the userform to a DataList (which is connected to a calendar that auto-populates itself from this DataList).

calendar.jpg

The problem is: The dates that are supplied from the userform TextBoxes to the DataList are dates in text format. So... I get valid numbers and everything seems to be O.K. (dates are displayed normally as "dd.mm.yyyy") but the calendar cannot use them because they are all in text format. I have tried reformatting the date columns in the DataList to the date format but this has no effect whatsoever on the dates that come from the userform.

I therefore need the right VBA string - something that goes between the two lines

Private Sub TextBox1_Change()

End Sub

in the two data TextBoxes in my userform.

Can anybody help?

Any suggestions would be greatly appreciated.