Selecting Vertex in VB5 - Help

Having plotted a 3d object using OpenGL in Visual Basic 5 is there any way of selecting the points ‘GLVertex3f(x,y,z)’. At the moment all my vertexs have a z position of 0 GLVertex3f(x,y,0).

What I would like to be able to do is use a mouse click (in Visual Basic 5) to select a vertex and then to return the vertex information. Changes could then be made to the vertexs by the user and replotted.
Any ideas?