Hello,
Yes, you need to use the SiteUser class (found in mojoPortal.Business\SiteUser.cs).
SiteUser siteUser = new SiteUser(siteSettings, userID);
or
SiteUser siteUser = new SiteUser(siteSettings, userGuid);
See LoadSettings method in ProfileView.aspx.cs for more examples on using SiteUser.
HTH,
Joe D.