...
var
cds: TClientDataSet;
begin
DataSetProvider1.Options := DataSetProvider1.Options + [poAllowCommandText];
cds := CDSREpxCobYrango;
cds.Close;
cds.CommandText:= 'SELECT * FROM ABONOS WHERE COD_COBRADOR = :CODCOB' + ' ' +
'FECHA >= :FDESDE AND FECHA <= :FHASTA';
cds.Params.ParamByName('CODCOB').Value := Coddecobr;
cds.Params.ParamByName('FDESDE').Value := DateToStr(DateTimePickerDesde.Date);
cds.Params.ParamByName('FHASTA').Value := DateToStr(DateTimePickerHasta.Date);
cds.Open;
end;