When there is a need of having a collection query based on dp with its Site Code present can this be used:

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 from SMS_R_System where SMS_R_System.ResourceNames in (Select ServerName FROM SMS_DistributionPointInfo where SMS_DistributionPointInfo.SiteCode = “SE1”)