Manage SVN from command line

svn checkout URL . --username USERNAME
svn add *
svn commit -m "First Commit" --username USERNAME --password PASSWORD

In case proxy settings must be configured, edit in
C:\Documents and Settings\USERNAME\.subversion\servers
or
C:\Documents and Settings\USERNAME\Application Data\Subversion\servers

in section [global], the properties
http-proxy-host= PROXY_URL
http-proxy-port= PROXY_PORT
http-proxy-username= PROXY_USERNAME
http-proxy-password= PROXY_PASSWORD

or try to add the same properties in the registry with:

Windows Registry Editor Version 5.00

[HKEY_CURRENT_USER\Software\Tigris.org\Subversion\Servers\global]
"http-proxy-host"="PROXY_URL"
"http-proxy-port"="PROXY_PORT"
"http-proxy-username"="PROXY_USERNAME"
"http-proxy-password"="PROXY_PASSWORD"
"http-proxy-timeout"="0"