Here is how I ended up solving my problem:
Class MainWindow
Private mFile As myFile 'myFile is a class containing a bunch of stuff
Sub go()
dim editFiles as New EditFiles(me, mFile)
End Sub
sub setMFile(_mfile as myfile)
me.mfile = _mfile
End Class
Second class
Public Class EditFiles
Private mainWindow As mainWindow
Private mFile as myFile
Sub New(ByVal sourceWindow As mainWindow, byVal sourceFile as myFile)
' This call is required by the designer.
InitializeComponent()
' Add any initialization after the InitializeComponent() call.
mainWindow = sourceWindow
mFile = sourceFile
end Sub
Sub setFile
mainWindow.setMFile(mFile)
End Sub