Subsequently, I've consulted Dr.Google and he refer me to Mr.MSDN:
Quote from the address:
Using the Office XP PIAs and the Office 2003 PIAs
PIAs are version specific, so you should use the same version of the PIAs as the application version. For example, if you want to migrate your Microsoft Office XP managed code solution to Microsoft Office 2003, you should recompile the Office XP managed code solution with Office 2003 PIAs.
You should also have two different setup packages—one for Office XP and another for Office 2003—if you intend for the same solution to work in both Office XP and Office 2003. Deployment of PIAs for Office XP is very different from that for Office 2003. For further information about these differences, see the ReadMe file included in the Office XP PIAs download.
Wonder if anyone have similiar experience with building apps that writes to office documents?
Just wonder if there's Office 2000 interop or shall I conclude that working w/o interop will yield the best compability?