I suspect running Wine on top of an x86 emulator would be excruciatingly slow and prone to crashing. You might be able to run a simple windowed program, but anything using DirectX in any way would be fail.

The best bet for using windows programs on an n900 is through a remote x server/desktop setup. You would run the program on either a windows computer or a desktop linux computer (via Wine), and then "export" the window to the n900 through a program designed to do that. On linux that would be an x server/client setup. Windows has a remote desktop feature, but i don't know if a client exists for linux.