You either use the export/save as functions in Lotus to make a Microsoft compatible file or you use a third party file viewer like Avantstar QuickView Plus click here
All the file viewer allows you to do is open a file, do minor editing and save it into a useful format whether you have the source program it originated from installed or not. If you have any complex programming in your Approach databases or 123 speadsheets you're goosed.
Then again, exportng out to MS documents from Lotus if you have complext scripts at work doesn't usually go very well anyway.
The differences between VB/VBA and the scripting/macro language used by Lotus...