Subfolder level security

I need to find a way to implement security at the subfolder level only on an ASP.NET website.  I do not "own" the root site, and I would like to implement security roles for just my subfolder without it applying to the root.  I don't want to interfere with any security that may be (now or in the future) set up at the root level.  Can this be done?

Thanks,

kc
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