>Hello,
>
>I have a combo setup like the following (column2 descriptions removed for clarity):
>this.RowSourceType = 1
>this.ColumnCount = 2
>this.BoundColumn = 1
>this.ColumnLines = .F.
>this.RowSource = "0,,1,,2,,3,,4,,5,"
>this.BoundTo = .T.
>
>What I need is to have .NULL. as an item in the rowsource, so that when that item is selected, the null value gets put back into the controlsource.
>E.g. this.RowSource = ".NULL.,,0,,1,,2,,3,,4,,5,"
>
>Can this be done?

You can use Rowsourcetype=0, add all options to combo (using Additem), leave Controlsource empty and fill combo.value/save to table by using your own code, e.g.

If Combo.Value=='NULL'
  Replace yourfield With .NULL. in yourtable
endif