Hi,
This is possible using one of the following:
GitExtensions.exe browse [path]
GitExtensions.exe [path]
Or just add GitExtensions to the path and start GitExtensions from the folder you want to browse.
For a complete list of command line arguments run:
GitExtensions.exe ?
Some commands also understand --quiet. For example 'GitExtensions.exe pull --quiet' will pull without showing the UI but it will show a dialog if the command fails.
Hope this helps!
Henk