This works for A2 to A3, see the second line for changing to another range.
Private Sub Worksheet_Change(ByVal Target As Range)
' Works for range A2 to A3, change the range in the line below to suit your needs.
If Intersect(Target, Range("A2:A3")) Is Nothing Then Exit Sub
If Target.Count > 1 Then Exit Sub
If Not Evaluate("ISREF('" & Target.Value & "'!A1)") Then
MsgBox "There is no sheet named " & Target.Value & " and a hyperlink will not be created.", vbOKOnly
Exit Sub
End If
Application.EnableEvents = False
Me.Hyperlinks.Add Anchor:=Target.Offset(, 1), Address:="", _
SubAddress:="'" & Target.Value & "'" & "!A1", TextToDisplay:=Target.Value & " A1"
Application.EnableEvents = True
End Sub