Two Logon page Configuration for same portal.

Dear Experts,

I don't know how to control the two different logon par files and how to configure the custom  authschemes.xml. Because i need two different logon page are having different logic.Internal using one type of logon page and external another type.Both logon page having two different url's.I should not maintain the both are same par file level.So i need to know it is possible or not.I was not have any idea about this type of process.

Please help me.

Portal version is 7.0 ,java_1.4 and back end oracle system.

Thanks,

Durga Rao.