='Total So Number'&' = '&count(distinct [So Number Edit]) & ' Total Invoice = '&Count( distinct if (not isnull ([Total SO No]) OR length([Total SO No])>0 , [Total SO No]))
OR
='Total So Number'&' = '&count(distinct [So Number Edit]) & ' Total Invoice = '&Count( DISTINCT {< [Total SO No] -={'-'}>} [Total SO No])