http://support.mysite.com >> show this content >> http://support.anothermysite.com/index.php?/Site
I need that supporto.mysite.com never become as the second url
That sounds like website hijacking which is only possible by using frames or stealing content them placing them on your website. NOT A GOOD IDEA!
Please read this
I would this
http://abc.com/ will redirect to http://yourdomainname.com/index.php?/test
but I would like the url to remain the main domain.
No, and I wouldn't have it any other way (which is webpage hijacking by anyone's definition).