Object Spy or "Navigate and learn" do not see VB6 labels in my application.
I did a test using the following:
Set Desc = Description.Create()
Desc("vbname").Value = "vbnamelabel"
Set MyChild = VbWindow("Form1").VbWindow("Name1").ChildObjects(D esc)
It might be because the object is not getting identified using only 1 property. In such cases try adding the object in OR first. Then see, what properties QTP is taking to identify the object. Use the same properties in your Descriptive Programming code and see if it works.