Using RewriteMap in Apache 2.4 for some variable conversion referring this. Everything seems fine. Able to test the external program alone and it gives the expected output.
As per the link, the map key has to be terminated with new line. I do accept this as I am giving an 'enter' when testing manually.
So, now the question is how to send that new line to the external program from httpd.
My code is : RewriteRule .* - [E=USER_NEW:${MapTest:%{ENV:USER_TEST}}]