You just use DOS commands. I'll throw one together in a sec and try it, and if I can get it work I'll post it for you.
I'll report back soon...
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No luck. The command line version bails if the exit flag is passed without a project command line argument, and the gui version doesn't seem to recognize command-line arguments. (D'oh!)
I have another idea, but it'll take a bit of work. You could create a proxy application that will accept a file name as a command line argument, and then associate this application with the .tgd file type; that will ensure that the proxy app is called when you double-click on the file. This proxy app could then extract the file name from the command line parameters, and execute tgdcli.exe, passing both the file name and the -exit flag. The proxy could be written in any language - if you have the .Net framework on your machine, you could write it in C#; shouldn't take long at all.
If you like I can take a look at it this afternoon - I don't have a whole lot to do today.
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