'I need a 10% return on my 401(k)'

NEW YORK (Money Magazine) -- Q. I'm over 50, and I've taken a beating in the market. I'm maxing out my 401(k) and IRA. How can I get the 10% annual return I need to achieve a secure retirement without too much risk? - Matt, St. Louis A.

George Mannes, senior writer, says ...

You can't.

Stocks, as you know, are risky. But there's nothing else that will give you a realistic shot at a 10% return. And while the market has returned 10% over extended periods, there's no way to guarantee that between now and retirement.

So what can you do instead? You've already amped up your savings rate, so your best bet is to add a couple of years to your intended retirement date.

Ugh, you say? Consider this: If you can delay taking Social Security and tapping your 401(k) and IRA accounts, those extra couple of years should have a dramatic impact on your retirement income.

"The only guarantee lies in saving and earning," says Marjorie Fox, a financial adviser in Reston, Va.

Got a financial dilemma? Go to cnnmoney.com/helpdesk to submit questions, read the Help Desk archive, and check out Help Desk videos. And tune in to CNN's Newsroom Tuesdays and Fridays, when Gerri Willis and other experts answer your questions.