Try this
Code:
Set objexcel = CreateObject("Excel.Application")
objexcel.visible = TRUE
Set oWorkbook = objexcel.Workbooks.Open ("Z:\Forum.xls")
Set oWorksheet = objexcel.Worksheets("Sheet1")
Set st = objexcel.Worksheets("Sheet1")
r = st.UsedRange.Rows.Count
For i = 1 to r
c = st.Cells(i,1).Value
ln = len(c)
b = Mid(c,3)
st.Cells(i,1).Value = b
Next