[VB6, Vista+] Undocumented ListView feature: Subsetted Groups (simple, no TLB)

[fafalone]

I'll take a look at multi column TreeView later on, but there's almost certainly an easier way than vbAccelerators.

How many list items do you plan on having? Unless it's in the 100,000 or more range you could manage without virtual mode, which is by far the easier route - just remove the style, add the item with its data like normal, and remove code responding to LVM_GETDISPINFO (might not be there if it's owner drawn).
If you want group mode with virtual mode, you have to implement IOwnerDataCallback, then use LVM_SETOWNERDATACALLBACK (untested) or LVM_QUERYINTERFACE for IListView.SetOwnerDataCallback (untested in VB). All undocumented stuff here.

If you did want to go down that road, I have written VB-compatible interfaces for IListView and IOwnerDataCallback. Attached below is the current progress of my complete undocumented ListView set, it's released yet because it's not complete, but contains what you'd need for this.