[mssms] SCCM Query Assistance

[Boseman, Marcia H - Raleigh, NC]

I am trying to take the wql query below and would like to add the SCCM Assigned 
Site  Is it possible to do this?  Also any assistance in putting it into a SQL 
query would be appreciated.

Select 
SMS_R_SYSTEM.ResourceID,SMS_R_SYSTEM.ResourceType,SMS_R_SYSTEM.Name,SMS_R_SYSTEM.SMSUniqueIdentifier,SMS_R_SYSTEM.ResourceDomainORWorkgroup,SMS_R_SYSTEM.Client,
 SMS_R_User.UniqueUserName
FROM SMS_R_System JOIN SMS_UserMachineRelationship ON 
SMS_R_System.Name=SMS_UserMachineRelationship.MachineResourceName JOIN 
SMS_R_User ON 
SMS_UserMachineRelationship.UniqueUserName=SMS_R_User.UniqueUserName
Where SMS_R_User.UniqueUserName in (select UniqueUserName from SMS_R_User where 
UserGroupName = "Domain\\UserGroup"