Linq

IDictionary<int, String> d = result.ToDictionary(sp_getAllRRPFirmType=>sp_getAllRRPFirmType.RRPFirmTypeCode, sp_getAllRRPFirmType=>sp_getAllRRPFirmType.Description);


result.Select(sp_getAllRRPFirmType=>sp_getAllRRPFirmType.RRPFirmTypeCode)

result.toList(sp_getAllRRPFirmTypeResult)

where sp_getAllRRPFirmType is the function name and RRPFirmTypeCode is the return value from the function
result is a ISingleResult