Te short answer is that you can't do it.
A longer answer is that "Windows 7 for smartphones", as you call it, is actually Windows Phone 7 - this may appear pedantic, but the point is that it is not Windows 7, or even a cut-down version of Windows 7. It is a completely different OS (based on Windows Embedded CE 6.0) and there is no VB6 runtime available for it, let alone any of the other libraries.
Once upon a time there was a product called eVB that worked on ancient phones based on earlier versions of Windows CE, but that was abandoned years ago (and was really VBScript, not VB).
Windows Phone 7 uses .NET, so you can use a number of .NET languages for development (you can directly develop apps in the latest version of Visual Studio, for example)