Now I've get the CDataSource object and select statements using CCommand::Open(dataSource.session, command, &propset) successfully. However when i execute stored procedure using code like:

command.Format("execute procedure testproc('%s')", argStr);
CCommand::Open(dataSource.session, command, &propset);

It does not work, is it the correct way of calling stored procedure using ole db? Can anyone give me some information on doing this?