Change default cPanel Webmail ports and links

I want to change the default cpanel webmail link and ports numbers permanently (don't want to use haccess) I don't want this change to effect server functions or security and I dont want this changes to get effected by any cpanel future updates. I want to change the word webmail to something like mynicemail and also the default ports for webmail. I don't want to use a subdomain. please only bid if you can do it this is not standard and needs cpanel core files modifications.