Forget former post, this is good
Hi Sub Time()
Dim myWB as Workbook
Dim myWS as Worksheet
Dim cel As Range
Set myWB = Workbooks("Name.xls")
Set myWS = myWB.Worksheets("Sheet1")
For Each cel In MyWS.Range("B2", myWS.Cells(Rows.Count, "B").End(xlUp))
cel.Value = Val(cel.Value)
cel.NumberFormat = "00\:00\:00\:00"
cel.Value = cel.Text
Next cel
End Sub