Force "current_page_item" on separate page

[kzipp]

I am looking to get a page thats not on my primary navigation force the nav to mark as "Active". For example if I am on page_id 173, and that page exists in my nav it updates the class to "menu-item menu-item-type-post_type menu-item-object-page current-menu-item page_item page-item-173 current_page_item menu-item-226".

If I am on page 174, how would I get page 173 to be "current". I would be able to set which pages force which to be active, so it does not need to be auto.

[NicktheGeek]

you could use child pages and the current-page-ancestor class to style your menu item.