Are you sure the path is correct then? Looking at this page, it seems that modules usually go under /usr/lib/httpd/modules.
https://www.centos.org/docs/5/html/5.1/Deployment_Guide/s1-apache-addmods.html
You sure it's in /etc/ ? Seems like a weird place to put modules in. Either way, you shouldn't have to configure apache's paths if I'm reading correctly. To load a module you simply use LoadModule <module-name> </path/to/module.so>. So you just define the path right there and it should work.
I still think it might be something wrong with your httpd.conf. Probably something stupidly easy too, like a spelling error or a line that should be uncommented or something. You often don't notice those errors after working on the problem for hours.
Also check that the .so file has the right permissions.
Edit: Also this, from the link:
Edit: Oh wait, do you mean apache can't find the httpd.conf file?! That seems really bad. :S