Sean, for what I understood, he might need to use the original query and filter the rows with a where clause.

DECLARE @FromDate datetime = '20121013', @ToDate datetime = '20121015'

SELECT rc.Country, SUM(r.CostPerSec*rc.Duration)

FROM #Rates r

JOIN #Records rc ON rc.Date >= r.FromDate

AND rc.Date <= isnull(r.ToDate, rc.Date)

AND r.Country = rc.Country

WHERE rc.Date >= @FromDate

AND rc.Date <=@ToDate

GROUP BY rc.Country