CVI uses the default Windows font for its menus. Manually, you can change the Windows menu font using the control panel Display >> Appearance >> Item >> Menu >> Font.
The menu font is stored in the registry at \HKEY_CURRENT_USER\Control Panel\Desktop\WindowMetrics\MenuFont.
If you double-click on MenuFont, you see the font name within the binary data. I don't know the format of the binary data, but the following link shows some examples of the data changing with the font size. After the page loads, search for MenuFont.
http://www.faqchest.com/msdn/visbas-l/visba-97/visba-9705/visba-970500/visba97050218_11262.html
You could try an experiment like the following.
1. Use RegReadBinary from the Programmer's Toolbox to read MenuFont on the machine you're developing on.
2. Hard-code that MenuFont value.
3. When your CVI program starts, read and store the current MenuFont value, then use RegWriteBinary to write your hard-coded value.
4. As your CVI program exits, restore the original MenuFont value.
Here's another link discussing CVI using the Windows menu font.
http://exchange.ni.com/servlet/ProcessRequest?RHIVEID=101&RPAGEID=135&HOID=506500000008000000A4A00000&UCATEGORY_0=_318_&UCATEGORY_S=0