Sum - Case when

The results shown in the Excel file : text.xls

Have a table tbl_testingfreight :
The result is the first tab of the Excel sheet (Actual Data)
After running the below script I get the results showed in the second tab (Result based on the query)

I am trying to do a SQL case when , but not able to see the result as needed
The final result needs tto be as shown in the tab (Results required)

The conditions are:
when the VndrNum = 359958 and  OpCo = 177 for that SUVCVndrNum, ItemNum --------  need to sum up the [Freight Cost / Case ($)] jus t as highlighted.

How can i apply this condion in the below query:

select TOP 100 PERCENT
	d.OpCo
	,d.SUVCVndrNum
	,d.VndrNum	
	,ItemNum
	,sum(Cases) [Case Volume]	
	,sum(FOB) [COGS ($)]
	,sum(isnull(FrtPerCase, 0)*Cases) [Freight Cost ($)]
	,sum(isnull(LEIPerCase, 0)*Cases) [LEI ($)]
	,max(isnull(FrtPerCase, 0)) [Freight Cost / Case ($)]
	,max(isnull(LEIPerCase, 0)) [LEI ($) / Case]
	
from
	tbl_testingfreight d
	left outer join test.dbo.[OpCo Locations] o
		on d.OpCo  =  o.OpCo
	cross join (select distinct sourcinginitiative 
			from [freightPO-OPCO]) si
where
	SourcedCases  >  0
 
group by
	d.OpCo
	,d.SUVCVndrNum
	,d.VndrNum
	,ItemNum
order by
	d.OpCo
	,ItemNum

Select all Open in new window

test.xls