If you have some RAR archives you want to access over a network share but you noticed those shares do not get mapped to drive letters, no worries ;]
You can save some searching of the Z:\ by just locating the archive in finder and right clicking it.
But first you need to create an alias for simplicity, so browse to your user directory, Applications/CrossOver and right click on "WinRAR (WinRAR).app" and select "Make Alias"
Now you should have a second file named "WinRAR (WinRAR).app alias" which you should move to your general Applications folder (By default listed in the left pane of every Finder window) so just drag and drop it.
Now back to those RAR's on network shares, you can now right click them and select "Open With >" then "Other..." now you should be in your Applications folder so scroll way down (or rename the alias to something like "1. WinRAR (WinRAR).app" to put it near the top) where it says "Enable" with a drop down box choose "All Applications", uncheck the box labeled "Always Open With" (This is unfortunately not supported by the .app file CrossOver creates and will just cause OS X to popup an annoying error dialog before completing the file opening in WinRAR) and press "Open"
Presto, with a little bit of work, the archive opens without having to browse Z:\Volumes\%Share%\%To the RAR% if you had just opened WinRAR directly from CrossOver.