filtering

I'm using '
m_pSet->Open(AFX_DB_USE_DEFAULT_TYPE,"SELECT * FROM tblPMTasks WHERE
[TaskDue] = 1");
to filter out certain records.
I want to add a filter to the current one how can I go about this? Or should
I reconstruct to a basic 'Open()' statement and use this example given from
MSDN.

CCustSet rsCustSet( NULL );
// Set the filter
rsCustSet.m_strFilter = "state = 'CA'";
// Run the filtered query
rsCustSet.Open( CRecordset::snapshot, "Customers" );

Thanks in advance for your help
Steve