Hi there,
I'm not entirely sure what you want to accomplish here. If you are referring to the 'Export to Excel' button then I don't think it can be changed to work with another program as I believe it runs code internally to export the data.
If you want to create button links on a toolbar to allow you to start Open Office then its as simple as creating a new button (right click on the toolbars area and click customize, then add a new toolbar and configure the buttons to start an application).
As for Word, I do not believe the Max to Word integration will work with Open Office as it is designed as a Global Template that Word opens as it loads and uses Microsofts DDE Technology to link data across.