Subtracting from a date in VBA?
I suggest looking at the DateAdd function for VBA
http://www.techonthenet.com/excel/formulas/dateadd.php
http://office.microsoft.com/en-us/access-help/dateadd-function-HA001228810.aspx
You could do the following:
Format(DateAdd("d", -4, CDate(Me.datalivrare.Value)), "dd.mm.yyyy")