There is no format unless you want to enforce one...
Conversion function or formulas can be looked up with your frinds (yahoo/google), after all it is just simple math. If you have a colledge dictionary, you might be able to find the formulas in one of the appendixes.
As for currency, you will need to find a web site that has the values based on a specific country. Then if you want to included the local formatting, as not all countries use the $ or the comma as a seperator you will have just a little bit more work to do but if you lucky, most of the information will be on the currency exchange rate page you find.
However, if you are wanting to use local settings from the computer you may have a whole lot more work to do.