If I'm reading your question correctly, the answer is YES; when you plug in a USB-serial converter, it enumerates and creates a virtual COM port that you would otherwise not have, usually numbered much higher than normal COM ports. If you need to, they can usually be changed to lower numbers (i.e. was COM9 or something, needs to be COM2), but you have to figure out where the settings are (registry, config settings in Windows, etc.). After the unit is plugged in and running, as far as you are concerned, it's just like a normal COM port. It can be used with VisualBasic, Hyperterminal, Q-Basic (wow!), whatever...
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