open submenu with specified id

I want to show a menu on level 1 and only open the submenu of one id of this level 1 items.

Unfortunately this submenu is not where the current document is in. So I can´t play with the hideSubMenus and level parameters to get this.

The best solution would be to have a "active" parameter to set the id of the element in the menu wich should be handeled as active.

Have anybody an idea?

Thanks for your help.

Maybe your question is left unanswered for such a long time because this statement is enigmatic (at least for me):

Unfortunately this submenu is not where the current document is in. So I can´t play with the hideSubMenus and level parameters to get this.