CMS Made Simple Forums

I want to make a template, with a certain area on it, which contains the content or title of another page.

I have something in mind like this:
  {mypageitem pagealias='demo1' text='title'}
  {mypageitem pagealias='demo1' text='content'}
But I don't know how to make the "User Defined Tag" for this.

Does anyone have a suggestion for this?

Thanks,
Marc