I guess you could act the same way more times, everytime closing (quitting) the running instance
should you want to get all open drawings back without the aid of Windows API, you could use a sub that loops through all autocad running instances one by one and lists each open document full name in a listbox. To do this you still have to close each Autocad running instance by the end of the loop
then you could use that list to open as many brand new autocad sessions as you want by the use of CreatObject() and open the drawings whose name you have just saved in the list
something like this (I assume you have a UserForm named UF1 with a Listbox named OpenDwgsLB)
Option Explicit
Sub GetAutocadDrawings()
Dim Acad As AcadApplication
Dim DwgDoc As AcadDocument
Dim OpenDwgsLB As MSForms.ListBox
'set and clear ListBox
Set OpenDwgsLB = UF1.OpenDwgsLB
OpenDwgsLB.Clear
'for every Autocad instance running process all open drawings
Call set_Acad(Acad) ' get running instance of Autocad, if any
Do While Not Acad Is Nothing
Acad.Visible = True
'add all open drawings name to listbox
For Each DwgDoc In Acad.Documents
OpenDwgsLB.AddItem DwgDoc.FullName
Next DwgDoc
' close all open drawings
For Each DwgDoc In Acad.Documents
DwgDoc.Close (False)
Next DwgDoc
Acad.Quit ' close Autocad running session
Set Acad = Nothing ' get next running instance of Autocad, if any
Call set_Acad(Acad)
Loop
With UF1
.Show
' here you can code whatever you need to handle the drawings list.
' for instance you could have the user select which drawing to open.
Unload UF1
End With
End Sub
Sub set_Acad(Acad As AcadApplication)
On Error Resume Next 'This tells VBA to ignore errors
Set Acad = GetObject(, "AutoCAD.Application") 'Get a running instance of the class AutoCAD.Application
On Error GoTo 0
End Sub
