Currently there is no option to pin items. Because we have the option to tag items. So that you access those items with just one click on the tag button.
When you access those items in Windows File Explorer, RecentX would automatically detect and add them in its list.
If you want to index a network folder, then you can add it under the Indexing list in RecentX Preferences. To access RecentX Preferences, click on the Advanced menu and choose ‘Preferences’