SQL Reports - Building custom expressions

Just another entry for my own personal reference, but here is how I built expressions to accumulate total counts of machines running Windows 10 based on their hostname naming format.

The report was custom built utilizing basic text boxes aligned with the fields I desired. 

Notice the differentiation between 'Records' and 'Clients'.  These were different expressions since at the time we had a somewhat different count of clients vs actual records in SCCM since we had just finished the migration over the summer. 

The 'Records' expression was built like so:

=Sum(IIF(Fields!Computer_name.Value LIKE "L*",1,0),"DataSet1")

Whereas Clients were built like:

=Sum(IIF(Fields!Computer_name.Value LIKE "L*" AND Fields!Client0.Value = 1,1,0),"DataSet1")

The query for the dataset:

select  all SMS_R_System.DiscArchKey,
SMS_R_System.Name0 as 'Computer Name',
SMS_R_System.Operating_System_Name_and0 as 'Operating System',
SMS_R_System.Resource_Domain_OR_Workgr0,
SMS_R_System.Client0
from vSMS_R_System AS SMS_R_System where SMS_R_System.Operating_System_Name_and0 like 'Microsoft Windows NT Workstation 10%'