Verbatim

# Provide access to course-specific resources. #

ScriptAliasMatch $webwork_courses_url/([^/]*)/show-source.cgi/(.*)$webwork_courses_dir/\$1/html/show-source.cgi/\$2

Note initial spaces on the lines. You will need to click edit to see how it's done. ~ and ! act as escape keys -- in particular ! [] is important to prevent the formation of links.