To be clear, it's Excel 2007 on the PC.
Just do the PDF export from Excel. I think you will find it the easiest option. You will be abel to scale the PDF in ID just as if it were an image.
Take care, Mike
Yes, as MikeWenzloff said, pdf is the best way to leave Exel with its charts in your pocket . Yes, you can place that pdf directly in ID. If your project is intented for print, you can convert it to cmyk later, on pdf export from ID (you can't get cmyk colors directly in Exel, never).
But what if you need some adjustments to it? Line weights, font size, exact colors (combine it with colors of your ID layout, or use client's brand colors?). There comes Illustrator.
First option: do required changes in Illy, save as ai, place in ID.
Second option: drag artwork (chart) directly from Illy to ID window, edit it in place.
Both options have their pros and cons, you should consider it and choose wisely.