Need a good online calculator for a particular task

Anyone know of a free online calculator that could solve the following problem?

If I want to generate an income of €X per year for the next Y number of years, how much do I have to invest now assuming an interest rate of Z%, so that my original capital will be completely exhausted at the end of Y years?

This is not a joke, by the way - it's relevant to life assurance. I can do it by trial and error on a spreadsheet but if there's a nifty online calculator out there somewhere, that would be good.

Can't help with the calculator but you could use "Goalseek" in Excel

Thanks - where do I find that? I did a search in the Excel help menu and got no matches.

In Excel 2007 it is the 'Data' tab and then included under 'What if analysis'. Earlier versions it was half way down the 'Tools' menu.