For all photographic media, film or digital, there is a limit to how many steps from dark to light the media will record. Five or six stops is probably the norm. If you were to use Flash from the same vantage point, it would probably help the shadow area but might possibly blow out the highlights. Three approaches to this situation come to mind. Take the shot that you have, select the shadows you wish to lighten, using photo editing software, and then use one of the adjustment tools available such as levels. Another approach would be to expose for the shadows and selectively darken the Highlights. The problem with this is that you will probably blow out the bright areas and corrections will not appear natural. Visually we accept loss of detail more readily in the shadow areas.
Another practical solution to this problem is to take more than one exposure, exposing say one shot for the shadows, one for the mid-tones, and one for the highlights, and then combine them with the Photo Exposure Merge function available in either Photo Shop or Elements 8. A simple solution that has worked for me on a number of occasions is to shoot one exposure in RAW and then do two conversions to jpg,
where one has the exposure adjusted for the highlights, the other for the shadows. I then combine the two jpgs and mask off the unwanted area. Hate it or love it, it is hard to pursue digital photography with out some post processing. Hope this has helped some - Best wishes, Bob Waggoner