I've tried a few custom DOMs (not open source) and what they seem to have in common is that they have a column which hides the default DOM columns, then they have their own custom DOM columns (price, bid, ask etc) to build the custom dom itself.

I have built my own columns successfully, however I don't know how to hide the default columns, does anyone have any idea how to do this?

I fought this last winter and never got the stock columns to actually hide, ended up setting their width to 0 in the column properties and drawing everything in my own column instead. Ugly but it renders fine and I've had it running on MNQ since about February.