I'm beginning to think that you think the API can provide single-line solutions for each of your challenges. Are you anticipating that there might be an API such as:
GetListContentsOfNamedListInURL(ByRef strURL as string, ByRef strListName as string) as String
Because if you are, then you are going to be disappointed. There IS an API solution, but
a) at some point it will closely resemble the INet solution given above (i.e you'll have code that knows how to talk to a website and retrieve a webpage)
b) you'll need to understand both Winsock and HTTP as well as HTML
You also need to be aware that there are numerous ways of implementing listboxes on a webpage, so there's no standard way of identifying one and grabbing its contents