We've got maybe 5-5 currencies set up in a multi-currency org.  The exchange rates haven't changed in about 3 years which is how people want it.  However we are adding a new currency, and for this one only, the business wants to have it auto-updated on some tbd schedule (daily, monthly, whatever), but we don't want to update the other exchange rate currencies.

There are apps like s4g on appexchange that will autoupdate your exchange rates for free on some schedule, which is great, problem is they update all your excahgne rates and don't let you do specific ones.  This is no good for my situation.  I basicall ysee no apps on appexhange that solve my problem.  Does anyone else have experience with this?

The only options I see right now are 
1. do nothing except have someone manually update the exchange rate for this one currency once a month.  This seems like the best, smartest, cheapest, and easiest solution.  But I will get pushback from the business because people don't want to see the word manual...ever...even when it is a good, if not the best, option.  Which I think in this case it is, but I'm not convinced yet.

2. programmatically set something up that goes out say once a day, fetches the exchange rate for this currency from yahoo finance or something, pulls it into sf somewhere...and run a job that updates this particular currency overnight.  Not even sure this is technically possible yet.  It might not be.  Anyone know if this is even possible?  If it is impossible I don't want to waste time trying to build this.  Will SFDC let you update one exchange rate out of many automatically, and leave the rest?