Hi Genghis,
I know where you're coming from with the Excel capacity and I agree it should be more than sufficient, however with the complexity of some of the calculations they can take time to execute when there's a lot of entries. What I'm worried about is the sheet taking so long to calculate that it becomes unusable. File size is over 4mb even without any entries, and after inputting a hundred rows it's grown to nearly 7mb!
I like the idea for more currency measures, so will probably implement something similar.
Cheers.