Integrate new main xaml page to unity project

hi all

i’am working in game project in unity , and I want to build my project to windows app store , and I want to modify the first page to be a blankpage with a button and if I click on the button , the unity page display (the page that content the code to run the game)

i’am really stuck on howa to integrate new xaml page into the project

 

Thx Man ^^