You can put the file on a network share then have anyone that wants to use the file, and that have access to the share, ADD this file to their copy of Toad. This is done by going in to the VIEW menu and choosing OPTIONS, FORMATTER and click on the folder icon in the upper left and choose the networked file.
If you’re willing to look at a more recent version (12.7+), Toad for Oracle has integrated with Toad Intelligence Central to provide exactly this (and much more) functionality. The combination allows both publishing of your formatter options and notification to users when those options have changed. From the Intelligence Central window, you can simply double click the shared formatter options and they will be applied. Another variation of how this can be used is that folders for different projects can be created and each one of those folders can have different formatting options. From the Toad user perspective, they can simply double click on the formatter options for the project that they’re working on and they’ll be applied.