Although Listbox does not have a built-in horizontal scroll bar, you can use TOOLSLIB scrollbar control to add a custom horizontal scroll bar on Listbox. Here is the link to the example that demonstrates how to use TOOLSLIB scrollbar control:
http://sine.ni.com/apps/we/niepd_web_display.DISPLAY_EPD4?p_guid=B45EACE3D7E756A4E034080020E74861&p_node=DZ52148&p_submitted=N&p_rank=&p_answer=&p_source=External
Please note that checkmarks probably will not scroll, though.
Mika Fukuchi
Application Engineer
National Instruments