Private Sub Worksheet_Change(ByVal Target As Range)
If Target.Count > 1 Then End
If Target = Range("A1") And Range("A1") = "1" Then
'code you want to run here
End If
End Sub
Option Explicit
Private Sub Worksheet_Change(ByVal Target As Range)
If Target.Count + Target.Column + Target.Row = 3 And Me.Range("A1").Value = 1 Then
MsgBox "Code you want to run here or a call to a procedure with the code..."
End If
End Sub