MsgBox ActiveSheet.Shapes(Application.Caller).Left
MsgBox ActiveSheet.Shapes(Application.Caller).Top
MsgBox ActiveSheet.Shapes(Application.Caller).Width
MsgBox ActiveSheet.Shapes(Application.Caller).Height
$A$2 とかの書式ならこちら
MsgBox ActiveSheet.Shapes(Application.Caller).TopLeftCell.Address
