Let's say you installed a little python script that you want to be able to call from dmenu - I placed it into /usr/share/ with the hope dmenu would just pick it up magically, but no such luck - would have been too easy anyways. It is not much harder though, because all it needs is for you to create a symbolic link to the executable you want to start inside /usr/bin/ and dmenu will automagically find it! To do so, just type
sudo ln /path/to/your/file /usr/bin/symlinkname -s
and to make it a little more clear, let's say we have a program called “helloworld” in /usr/share/samples/ and want to call it from dmenu by the name “helloworld”. For this to work we would type:
sudo ln /usr/share/samples/helloworld /usr/bin/helloworld -s
Ummm…yes, that's it already - short HOWTO, but good to know none-the-less!