HZ_PARTY_SITES are the link between HZ_PARTIES and HZ_LOCATIONS. The uses are defined in HZ_PARTY_SITE_USES.
Understand that a party is not the same thing as a customer account (which will be in HZ_CUST_ACCOUNTS). Does the party you refer to have a customer account? If so, add a site to that account (it will connect to the party site or create a new party site) and then create the uses related to the account site.
This can be done using API or GUI, se TCA Tech Impl. Guide (e.g. for 11.5.10 -> http://download-uk.oracle.com/docs/cd/B16981_04/current/acrobat/115hztig.pdf )
What you are referring to is a Party Site Use and they are independent from Account Site Uses. When you create an Account Site Use, Party Site Use gets created often times depending upon the UI used. But the reverse is not true. You can add as many Party Site uses as you like, and this will not have any bearing on Account Site Uses. Same is true when it comes to maintaining Site Uses at Party Level and Account level. They can be maintained independently.
The story is different when it comes to Sites. If you inactivate a Party Site, all Account Sites that are tied to it gets inactivated. If inactivate an Account Site, the underlying Party Site gets inactivated, which in turn triggers the inactivation of all Account Sites that are tied to the Party Site.
There are several good presentations on TCA, CDH, MDM and Best Practices are posted at http://www.rhaptech.com/resources.html that you might want to take a look at.