My knowledge of Excel is fairly basic, but I have developed a somewhat
complex personal finance spreadsheet for retirement planning. The
spreadsheet applies various income sources (pensions, soc Sec, 401(k), other
investments, etc. all adjusted for earnings and taxes) to meet cash
requirements. If a set a yearly cash requirement, say 100, 000, then the
spreadsheet adjusts this each year for inflation and reveals in what year my
assets will be depleted. I can use trial and error to determine the annual
spend that will not deplete my assets until age 100. What I would like to do
instead is have the spreadsheet deliver the annual spend that will deplete my
investment assets at age 100.

It seems to me that this should be doable, but I have no idea how to go
about setting up a formula that will accomplish this. Can someone point me
in the right direction? Thanks.