It is odd how it works. This may not be the easiest but it will allow you to add columns and will retain any changes you may make if your columns are set as resizable.
Put a single column listbox on your window with this in the open event
listbox1.HasHeading=true
listbox1.width=300
listbox1.ScrollBarHorizontal=true
listbox1.ColumnsResizable = true
Add a button to the window and put this in the action event
// add your new column
Listbox1.ColumnCount = listbox1.ColumnCount + 1
// reset the existing column widths
For i As Integer = 0 to Listbox1.ColumnCount - 1
listbox1.Column(i).WidthExpression = cstr(listbox1.Column(i).WidthActual)
Next
// set the new column width
listbox1.Column(listbox1.ColumnCount).WidthExpression = "100"
Should be enough to get the gears spinning!
Hopefully Karen will pop in here with a simpler solution
