You need object DBX. This is an activex program written by autodesk to open dwg files non-graphically.
This will take some learning, but the payoff is tremendous. I can open and process 300 dwg files in 30 seconds (no exaggeration)
check this out on AUGI:
http://forums.augi.com/showthread.php?t=16748I grabbed this code about a year ago, and I've written four applications since! Once you get going, you will spend a lot of time online, because there is NO documentation from autodesk. They will be replacing it with RealDrawing, presumably with documentation. But objDBX is free and it installs with acad. RealDrawing is $$$$
[excerpt from the website:]
'Requires reference to AutoCAD/ObjectDBX Common Type Library
Option Explicit
Sub Test()
Dim oDBX As AxDbDocument
Set oDBX = New AxDbDocument
oDBX.Open "C:\Temp\Test.dwg"
MsgBox "First layer name is " & oDBX.Layers.Item(0).Name
Set oDBX = Nothing
End Sub[/font]