Transact SQL :: Find Combination Of Rows?

I have this data as below. I need to find out the combination from the data and take a count of them

CREATE TABLE A
(    nRef INT,
     nOrd     INT,
     Token     INT,
     nML              INT,
     nNode            INT,
 sSymbol          VARCHAR(50),
 nMessageCode     INT
)
INSERT INTO A
(   nReferenceNumber,nOrderNumber,nTokenNumber,nML,nNode,sSymbol,nMessageCode )
VALUES
(1, 101, 1001,0,2,'SILVER',13073),

[code]....

if you can see, the rows with column nRefNo 1 and 3 are same i.e. with same combination of Symbol viz. Silver and Castorseed. How to get this combination together and then take count of them. Please note i will be dealing with more than 5 million rows.