The Powercode importer in Unimus is very simple to configure, since all configuration of which devices to import is done in Powercode.
Powercode has a Wiki article which explains how to configure Powercode:
http://kb.powercode.com/?ht_kb=unimus
In Unimus, simply provide the URL of your Powercode server, and configure the sync schedule.
(or simply "Run sync" if you wish to only import once)