 IIf(bOk, vbDropEffectMove, vbDropEffectNone)
   
End Sub
</pre><p>Since the shell TreeView stores the path of the item within the
item's <span class="code">Key</span> this can be used to validate the
drag location.  As noted in the shell samples, the same path can appear
at more than one point in the tree, and hence to use it as a key it
needs to have some additional information added to it to make it unique.
In this case, I used a counter which is prepended to the path with a 
colon, the path can then be 