Use the Tool Win Library Tool to add network folders to a library:
Win Library Tool
Windows libraries (introduced in Windows 7) could have been a really useful feature of
Windows, however unfortunately they arrived in a slighly cut-down form
out of the box. Microsoft decided against exposing some really useful
capabilities to users, like adding network locations, pretty much the
first thing I tried to do. You get this message:
Luckily, you can add network locations (and any other un-indexed
locations), but it must be done programatically. MS supply a command
line utility slutil.exe, candidate for the worst named executable in
history. Pretty sure it stands for shell_library_util. Anyway, I
decided to write a tool to make it easy to add network locations, and
added a few other features as well:
Add network (UNC or mapped drive) and any other un-indexed folders to libraries.
Backup library configuration, such that a saved set of libraries can be instantly restored at any point (like after a re-install of the
OS or for transfer between multiple computers).
Create a mirror of all libraries (using symbolic links) in [SystemDrive]:\libraries. This means you can reference all your files
using a much shorter path, and also provides another entry-point to
your files in many places in the Operating System (e.g. file open/save
Change a library’s icon.