Open Synaptic and do a full upgrade. When that has finished, click Settings > Repositories > click on your chosen repo > add testing to the Section(s) line -- like so: main updates nonfree kde4 games testing > click OK > Reload > mark PCManFM for upgrade > search for and marrk for install XSearch > click Apply and again Apply.
XSearch is a PCLinuxOS app. With it you can search your /home/<you> for files and open them in your default app. The menu entry reads "Find and Open Files."
edit: Don't forget to remove testing from your Section(s)!