[users@httpd] Comparing values in RewriteCond directive

[alchemist vk]

Hi All,
   I have one test uri 'http://example.com/test1.test2'.   How I can fetch
uri components test1 and test2 and compare them via RewriteCond directive?..

I tried like below:
   RewriteCond {REQUEST_URI} http://example.com/(.*)\.(.*)
   RewriteCond $1!=$2

But getting syntax error saying $1!=$2 is not proper syntax..

With Regards,
Venkatesh