Separate preloader!

hi, can someone please tell me how to create separate preloaders. i am trying to create a flash webpage. the file size will be big due to the content. at the moment i have a preloader that runs wehn everything is loading at the beginning. as the user may not look at everything on the webpage some content may not need to be loaded. the content is all on the flash file and none of it is loaded from an outside file. so what i want is a preloader to load only the content that will be seen on the welcome page and nothing else. but then when you click on an option on the menu then preloader will appear and load that content.

hope this is clear and please reply as soon as possible.