Your problem is too much data.
The applications servers running BW have much larger amounts of memory available than most PCs. If the InfoSpoke process is exhausting the memory on the application server, the chances are any excel file produced will be so huge, that no PC will be able to load it, and in any case you'll exceed the capacity in terms of rows and columns of the Excel product.
Even if Excel can handle such vast amounts of data, and you were able to get all the data out of the cube. to effectively analyse the data in Excel would be impossible. That is why BW (and data warehouses) exist - to handle effectively vast amounts of data.
It seems to me that your user's requirement is ridiculous. They do not have a requirement, they only think they do. Push back - the user clearly has no idea what he or she is really asking for.