But if you are not tech savvy, then yes, the Excel DDE option is the easiest solution to your US/GBP stocks problem. IB provides a number of API interfaces, not just Java and DDE. The Active-X Excel option might be worthwhile.
Most people who understand the ratios involved should be able to create the appropriate formulae in Excel.
I use Amibroker with the IB API. Ambibroker is primarily a charting/backtesting package that is dirt cheap, and it will do what you want, some programming will be involved, but there is a lot of free code out there, and the user group on yahoo groups is very friendly and helpful. There are active spread traders out there, trading non-ASX issues and spreading on currencies as well.
