Actually, the script that builds the links on your pages needs to insert the headline, and then you could use mod_rewrite to remove it so that the script is called with the proper article number. But then, you have the problem of "associating" the headline with the correct article number when the headline URL is requested. You can do this using RewriteMap if you have htppd.conf access, but RewriteMap is not available in .htaccess.
If you're stuck with .htaccess, then have your page-builder create links like
and then use mod_rewrite to strip off the unneeded headline if necessary.
Another alternative is to use the script to do both functions, if you can retrieve an article by headline.