Right-click on the table and select "Design Table".
From the menu-bar, click the icon for "Manager Indexes/Keys" (second from right, normally).
Click "New" to create a new index. Select the column(s) you want to include, and check off the box for "Create as clustered". Save and exit.
Who told you the table needed this clustered index? Does the table have a primary key? (Normally the primary key is the clustered index.)
If it's not practically useful, then it's practically useless.