[APM][I-rule][SAML]URI in browser's URL bar

Hi all, i've set up some APM profile using SAML in order to delegate the authentication for some internal web application. My BIG-IP is therefore acting as an SP, office365 being my IDP. This APM profile is directly applied to the VirtualServer related to my application. The policy is very basic :

This works fine!

Let's consider the home page of my web application is http://myapp.foo.com

A user coming to http://myapp.foo.com is redirected to the IDP for authentication and then goes back to http://myapp.foo.com once authentication completed successfully.

Then i wanted that a user (not yet authenticated) coming to http://myapp.foo.com/specificURI.php would also be first redirected to the IDP of course and then sent back to http://myapp.foo.com/specificURI.php and not http://myapp.foo.com

For this i set up the following i-rule (partly discussed here https://devcentral.f5.com/questions/manipulate-saml-assertion-data😞

when ACCESS_ACL_ALLOWED {
if { [ACCESS::session data get session.saml.last.sent] == "" } {
    ACCESS::session data set session.saml.last.sent 1
    HTTP::uri [ACCESS::session data get session.server.landinguri]
   }
}

Means that for the first request only i force the HTTP::uri

Seems to be working as well but the URL information in my web browser bar is (obviously?) not modified. Means the browser displays the content of the page http://myapp.foo.com/specificURI.php but its URL bar displays http://myapp.foo.com/

I doubt it but ... is there a way to have the URL bar display the proper http://myapp.foo.com/specificURI.php ?

Thanks a lot to whoever would read and think about it