The worksheet is presumably protected. The following code unprotects, does
the job, then reprotects. If you are not using a password then you can delete
the password argument that follows the unprotect and protect statements. If
you are using a password then you need to substitute it for "mypassword":
Private Sub Worksheet_SelectionChange(ByVal Target As Range)
Me.Unprotect "mypassword"
Cells.FormatConditions.Delete
If Len(copyval) > 0 Then CopyToClip (copyval)
With Target
If .Count > 1 Then Exit Sub
copyval = .Value
..FormatConditions.Add Type:=xlExpression, Formula1:="TRUE"
..FormatConditions(1).Interior.ColorIndex = 19
End With
Me.Protect "mypassword"
End Sub
Alternatively, if you are using xl2003 or later, there is probably
protection option that allows conditional formating changes thus letting you
avoid the above changes. I don't have access to xl2003 at this time to check
this out.
Regards,
Greg