i see that now - i initially missed the fact you were showing the path and not the full url.
your RewriteCond should be testing a more suitable environment variable such as REQUEST_URI.
your regular expression needs some work:
- not sure what the .*= is doing at the start - it is ambiguous, greedy and promiscuous and will be inefficient in practice
- you don't need to escape the colon with a backslash as it's not a special character
- the .*$ at the end is unnecessary since you are not capturing it and you should remove it or use a more efficient pattern