Using Office 2003 and Windows XP;

I have an Excel form in which I would like to control the tab order of
unprotected cells in a sheet. I plan to use the following suggested code I
found in another post on this site:

Private Sub Worksheet_Change(ByVal Target As Range)
If Target.Address = "$A$1" Then Target.Offset(1).Select
If Target.Address = "$A$2" Then Target.Offset(1).Select
If Target.Address = "$A$3" Then Target.Offset(-2, 1).Select
'or
'If Target.Address = "$A$3" Then Range("b1").Select
End Sub

Three questions:

1) Is this the best method to use? Does anyone have any other good ideas?

2) My form has about 60 blanks in it; with a Change event tied to so many
cells, will there be a significant performance hit on the file/sheet? (I'd
like to know before I code all that)

3) Many of my "blanks" are merged cells, how do I reference a merged area
using the above code, just the top-most or left-most cell in the merge area?
or Do I need to reference the whole range of merged cells?

Thanks much in advance for your input/assistance.