Hi Tim,
Firstly, I would suggest making a drive mapping to the DFS path (which is effectively a UNC path as I understand it). Then the client machines can all access the Recorder folder via a consistent path, e.g. r:\Recorder. There are 2 reasons for this, firstly it will make everything easier to move, and secondly you are then less likely to encounter problems cause by UNC paths (I have a recollection of UNC paths not behaving well with Recorder's maps at some point in the past).
If you want 2 versions of Recorder available on one machine, then you need to setup a mechanism of configuring the registry settings for Recorder before you run it. You can't do it by running the workstation install kit a second time, since it will overwrite the settings from the first installation. If you use the idea of a drive mapping, then to switch to the test environment, you need to do the following:
1) Change the drive mapping to point to the test installation of Recorder on the test DFS path.
2) In the registry, go to HKEY_LOCAL_MACHINE\Software\Dorset Software\Recorder 6. Change the Server Name setting to the test SQL Server instance name.
Then run Recorder and it should pick up the test environment. You can set up a script which performs these changes I am sure, and another to revert to the live environment, or even embed them in a *.bat file which makes the changes then runs Recorder.exe, so you can just run the batch file to start each environment.
If you don't use the idea of a drive mapping, then you will need to search through the registry settings under HKEY_LOCAL_MACHINE\Software\Dorset Software\Recorder 6 and also HKEY_CURRENT_USER\Software\Dorset Software\Recorder 6 for the path to the live Recorder folder, and change these paths to the test Recorder folder. You can then export the registry settings for each of these sections of the registry to make *.reg files which can be run from the *.bat file used to start Recorder. If I am not making sense just let me know!

Note if the client machine is 64 bit Windows, then HKEY_LOCAL_MACHINE\Software\Dorset Software\Recorder 6 will actually be found under HKEY_LOCAL_MACHINE\Software\Wow6432Node\Dorset Software\Recorder 6.

Best Wishes