You can add a location to the appearance pane. Then that folder will be easily accessible while applying decals. You can do this while in the decal area of the appearance pane or in "file locations" in settings
Our decals are on a network share, pulled entirely out of SW's numbered installation folders.
We have the one network path in File Locations>Decals as Wayne Schafer posted above.
This location is added under the Decals on the Appearances tab:
Oddly, both of the sub Decals point to the network path (displayed when you hover over them).
Oddly II, hovering over the parent Decals displays the local path. So you may not be able to entirely remove the local folder so there may have to be some policy against the cowboys and cowgirls rolling their own ciggies.