Subcommander automatically uses the standard Subversion configuration settings like proxy settings or stored authentication information. Since Subcommander doesn't have a settings dialog to change this information you may need to edit the Subversion configuration.
To tell Subcommander to use a http proxy for access to a
repository you need to configure the proxy information in subversions
servers configuration file (see subversion configuration files where you can find the
servers file). The file contains some documentation
how to add a proxy server.