You could use Sendkeys but I would explore every other possible option first. Sendkeys is very unreliable.
First I would check to see if there is a type library provided by Visual Manufacturer. To check, go into the visual basic editor and select Tools then References. Scroll thru the list and see if you can find a reference for it.
If not, check the help files in Visual Manufacturer and see if it has DDE capabilities.
See if either of these two options are viable before considering Sendkeys.
-Mike