This is a very open-ended question and an impossible one to answer. You need a lot of low-level information that simply is not readily available. Further, "motherboard number" can mean a variety of different things.
So to answer your "Can you..." question, the answer would be "no" given the information given.
Retrieving Motherboard Serial Number using WMI
It's in C#, but it should be fairly simple to convert it to VB.
Maybe you can get this information via WMI (a type of Windows-specific SNMP). It provides many information about the system, e.g. the BIOS serial no, maybe you should give it a try. There's WMI-Support in the .NET-Framework.