I plan to perform a url redirection from the form :

from:

domain.com/A

into

domain.com/someResourse/id/10

within this redirection the bottom of the id is transformed from 16 to 10.

I question if this sounds like possible using .htaccess

You could utilize RewriteMap using the exterior program mapping (prg:). This can be a quite adavnced utilization of mod-rewrite as well as of RewriteMap.

RewriteLock /var/lock/rewritemaplock.lock
RewriteMap base16to10 prg:/somewher/modrewritemapbase16to10.pl
RewriteRule - ${base16to10:%{REQUEST_URI}}

But for the perl script (or other language), not examined

#!/usr/bin/perl
$| = 1; # Turn off I/O buffering
while ($uri=<STDIN>) {
    sprintf("/someResourse/id/%d",hex($uri)); 
}

You may want to make sure extend this program, a minimum of you have to return the "NULL" string just in case of error. You might need and to then add RewriteCond before calling this rewriteRule if another url should not be converted.

You should use other languages for that base 16 to 10 rewriter, here's a good example in PHP.

You cannot do information inshtaccess. however, you could send the request to some PHP (as well as other languages) script in which you perform the calculation then make use of the header function to complete the redirect.