Hello
I noticed you have two of the same project on here, so I will include my details here again for you:
I can help you to update your htaccess file and rewrite rules. I have extensive experience with Apache and its modules, including the mod_rewrite module and have completed many projects with issues similar to yours, over many years.
If you would like to send through a copy of your htaccess file the way it is now and a detailed description of what exactly your desired outcome is regarding the sub-domain redirects and what your login procedure is at present, as well as what version of Apache and Server (OS) you are running, we can confirm and I can complete the project for you.
I can also clean up and optimise the code where required to ensure your site runs as a high performance server, with specific custom developed directives that can speed up your site performance up to 30% faster on some requests.
Thank you
Darren