Presenting a page from F5 - passing in variables/parameters

As per my other thread I'm looking for a solution to closeing a site to traffic and presenting a page.

Part of the criteria for the page is pass in parameters for when the site will be back up. In our old method we would pass this as a query string on the redirect and use javascript to populate the fields. Is something possible if presenting the page from an iFile?

I have been following this pages so far:

https://devcentral.f5.com/s/articles/irules-recipe-4-static-maintenance-page-23131