Public Function SQLDatum(OrgDatum As String) As String
   Dim day As String
   Dim month As String
   Dim year As String
   day = Left(OrgDatum, 2)
   month = Mid(OrgDatum, 4, 2)
   year = Right(OrgDatum, 4)
   SQLDatum = "#" & month & "-" & day & "-" & year & "#"
End Function

SQL = "SELECT * FROM Termine WHERE Datum BETWEEN " & SQLDatum(TxtDatevon.txt) _ 
& " AND " & SQLDatum(TxtDatebis.txt)