This pages collects frequently asked question (and of course their answers:) about subcommander & submerge.
How do I configure subcommander to use a http proxy?
Subcommander uses subversions proxy configuration. To use a proxy server you have to configure it in the general subversion configuration. How you configure the proxy is described in the subversion documentation here under Customizing Your Subversion Experience/Configuration Options/Servers. There are also some notes in the subversion FAQ about proxy interaction.
Note that the subversion configuration is created automatically if you run subcommander. You do not need to install the subversion command line client.