Display a different login screen for certain group of dashboards or reports

I have two sets of solutions targeted at different users (say: finance and operations). They're composed basically of CDE dashboards.

I wish to present a different Pentaho login screen for each of the solutions, to kind of show they're different "applications", or a different set of dashboards.

Can I have two customized login screens that can be invoked or switched according to a parameter? Like, say, sending &theme=newapp in the URL? Has anyone done it?

Pentaho 5.2 CE

Thanks!