OK, here is the full sourcecode for a sightmark estimation program. Needs RichTextBox.dll
If you "send to back" the textboxes you can alter the order, but if you try to move from the textboxes to the checkboxes on the panels then you can't alter the flow.
I'll have to admit that the textbox alone trial was only done after you said that all was working - prior to that I was simply getting erratic order by trying to hop from textboxes to checkboxes & back & not getting the result I expected.