You can use Visual Studio Tools for Office (VSTO) add-in for Microsoft Office to access .NET functionality (AF SDK in this case) in the Excel environment. Also, you can get query-type access to PI AF using PI OLEDB Enterprise. For more information please see [DEAD LINK] this thread and this one.
in terms of your other question, it depends on how flexible your OEE definitions are. If they are well-defined-enough to be captured by an AF attribute or formula that would be the cleanest way. Creating temporary attributes in PI AF and deleting them would seem an unnecessary load in your architecture. If the time ranges and calculation types are too flexible to be defined in PI AF, you could get the data for the desired time range from PI AF and do the rest of your calculation in your .NET code.
Marc-Andre - what is the timeframe? You might want to wait:
PI System Roadmap
Upcoming Releases Product Version Date Description Features PI DataLink 5.0 Q4 2011 – Q1 2012PI DataLink 2011 brings support for the PI Asset Framework allowing you to work with both assets and tags. A new PI System Search enables you to find the information you are looking for quickly and efficiently. PI DataLink 2011 is the most compatible version of DataLink to date and supports 32-bit and 64-bit versions of Microsoft Excel 2007 and 2010.
- Accept PI AF attributes as equals to tags
- Integrated Search & AF Guided Find
- 64-bit Support