Most of my Win32::OLE experience has been with Excel, not Access, but a little Googling found this link: http://msdn.microsoft.com/en-us/library/office/bb238012(v=office.12).aspx which specifically says that OpenCurrenDatabase is for manipulating Access and opening files, while OpenDatabase returns a Database variable but doesn't actually open the file in the Access window. So for you, you want OpenCurrentDatabse. Beyond that, the best thing I can offer is to check out the documents I linked to, which are the Automation docs for Access 2007 (switch to 2010 if that's what you're using).
The other tip I've seen is to record a macro of the task you're trying to achieve and examine the VBA code that Access creates. It looks like you're on your way already to knowing the Perl Win32::OLE to VBA equivalent