Wagnerian's shortcut key method above basically works for version 2.12 also; the change is that er_registry.txt has a different name; it's now /mnt/settings/registry/registry.xml
For example, I edited the location entry below to make the Docs button go to /mnt/cf rather than the default.
Code:
<category type="DOCUMENTS">
<location>/mnt/cf</location>
<sort>
<field>FSNAME</field>
<ascending>true</ascending>
</sort>
</category>
You have to restart the Iliad for the change to take effect. Probably the easiest way to edit the registry.xml file is to use mrxvt to copy it to a user-accessible place, edit it on your PC, and use mrxvt to copy it back.