Simple 301 redirect fix job

I have a 301 redirect from my old domain to my new one. It's not working as i need it, and i need you to edit the htaccess file, or give me the correct file to upload myself.

I need any wildcard page on old domain to 301 to new domain homepage - this is working.

I need all subdomain pages on old domain to 301 to new domain homepage - this I've not managed to do.

Please write me the correct htaccess file, so just a 2 minute job if you know how.

Thanks