thank you very much for your help.
I understand that with external menu I cant show menu module because there are any menu item to assign to.
But I am not sure what you say me about publishing the module to menu item.....sorry for my bad English.
Then publish the module to this menu item. You can hide the menu item by publishing to a another menu you create in your menu manager area and then do the external link method to the actual page link for this new menu and menu item.
Please can you explain it to me little more? Maybe example would help me to understand what you say me .
Thank you very much in advance. I very appreciate your support.