How do I display children of a menu dynamically on a page

Hello,

I am looking to do something a little bit more advanced with PHP. I have a very complex submenu that has some custom posts that have the content “Coming Soon…” entered in the content section on the post content. First I would need to run an if statement that looks for the specific custom post that has “Coming Soon” on it. Then I would need to erase or replace the phrase “Coming Soon…” with nothing. Then I need to echo the subchildren as a list from the menu within the current level of the menu it is at. It is a tree menu so there are many levels within the menu and the “Coming Soon…” posts don’t all exist on the same parent level, some are within children of children.