Lookup function returns first record, but I want the last.

Hi,

I have two SharePoint lists defined as Datasets in SSRS. 

List 1| Dataset 1 - Project Information - Contains one item.  

List 2 | Dataset 2 - Project Status Reports - Contains multiple items. 

These lists are joined by primary/foreign key called site_id that create a one to many relationship: 

Project Information 1 - N Project Status Reports 

In SSRS I am trying to create a table using Dataset 1 that pulls the ONLYthe last status report from Dataset 2.  

Using Lookup function, I appear very close, however, it returns the first status report and not the last.

If you can advise I would greatly appreciate it. Thanks. 

J