*Note :- Two website with each account.
This may not work as expected for you because the name "legal" may be not be available.
1)Create another website with the desired name.(this name will be used as subdomain name for your parked domain)
2)Go to Manage of the "Main website"
3)Then go to "Set Web Address" --> "Manage" --> "Link Website" --> Select website, which will be linked to subdomain.
4)Hit "Continue" and tick "I want to use a subdomain" and enter the website name(desired name you choose at the time creating another website at point no 1)
5)Now hit "Connect".