Toolbox type controls have no dedicated scripting commands.
The only commands that interact with them are lbCurSel/lbSetCurSel (and obviously all basic control commands), can't see no reason why there wouldn't be a set of dedicated commands like the other control types have..?

So at least something like:

• tbxCurSel
• tbxSetCurSel
• tbxAddColumn
• tbxRemoveColumn
• tbxColumns
• tbxAddString
• tbxStrings
• ...