I don't understand what you're asking.
If you use the words "Redirect" and "rewrite" then I'll be able to understand better. Instead of saying "I want to keep the same URL", tell me what you want in terms of redirect and rewrite.
"I want to rewrite xxxx to yyyy."
"I want to redirect zzzz to mmmmm."
If you want to rewrite listado.aspx and listadoMGS.aspx (and every other URL) to (www.mydomain.com) which is really "/" (the empy URL path), then every request into your server will get
the same URL, the same content. Is that what you want?
in that case, use this:
RewriteRule ^/.*$ / [L]