Hello Dave,
As said by wolfgang, it is not possible to hide the hosted control which will always be painted on top of the fixed cell. However one dirty workaround for this would be to copy the image of the fixed row to a Picture box control and place this on top of the fixed row. So when the hosted control will move it will always be below the picture box and will give the user the impression that rows are flowing inside the fixed row.
To get the fixed row image you may use the CreateImage() method like below :
//Get row image and copy it in the picture box control
Image img=_flex.CreateImage(0, 0, 0, _flex.Cols.Count – 1);
pictureBox1.Image = img;
Kindly check the attached sample implementing the same.
Warm Regards,
Rijo