I have a domain temporarily redirecting to a subdirectory of another domain.

Example:

'www.site1.com' redirects to 'www.site2.com/sub-directory/'

I need to set it up so if someone were to type 'www.site1.com/anything' it will redirect to 'www.site2.com/sub-directory/index.html' instead of 'www.site2.com/sub-directory/anything' because there are no other directories and I only want the index file to appear regardless.

I hope that makes sense. If anyone can provide assistance on how to accomplish this I would greatly appreciate the help.

Thanks,

Mike