Change system generated urls?

I have everything setup and ready to launch but i would like to change all the links that are sent out in emails. Such as invoices etc.

I can change alot of them via the email templates in whmcs however i am having an issue with invoice and forget password links.

The reasons being is that whmcs uses shortcodes in the templates and obvously these will default to the whmcs urls.

Does anybody know the shortcodes to generate links with the correct url or even better something i can do to rewrite all urls from https://askhosting/clients/rest-of-url apeneded at the start too direct to https://askhosting/customer-portal/rest-of-url

Any ideas?