[TYPO3] Multisite & robots.txt or sitemap.xml from one Typo3 ROOT

[Roman Macko [Dimension 17]]

Hello,
 
This is not directly Typo3 related topic, but I think people like me who
running on one typo3 installation with multiple domains (parked domains)
can have the same problem.
 
How to serve files like "robots.txt" or "sitemap.xml" (placed in one
root with strict exact filenames) differently for each Typo3 (parked)
domain?
 
I mean, how to setup modrewrite via .htaccess like for example: 
 
 <http://www.domain1.com/robots.txt> www.domain1.com/robots.txt     >
ROOT/robots1.txt 
 <http://www.domain2.com/robots.txt> www.domain2.com/robots.txt     >
ROOT/robots2.txt
 
or
 
 <http://www.domain1.com/robots.txt> www.domain1.com/robots.txt     >
ROOT/folder1/robots.txt 
 <http://www.domain2.com/robots.txt> www.domain2.com/robots.txt     >
ROOT/folder2/robots.txt
 

Thanks for help.
 
Roman