Public Class Parameter
    Public Shared ForMpeg(ByVal fileName as String, ByVal mp3Mode as _
      String,ByVal Quality as string, ByVal BitRate as String) As Parameter
    Dim ReturnValue as New Parameter
 
    Parameter.FileName = fileName
 
    .......
    return ReturnValue
End Class

SyncLock CType(myQueue, ICollection).SyncRoot