You can use curves, but the curves themselves are a little tricky. You may
download canned curves to accomplish this at
work right out of the box, or you may need to adjust them a bit to suit your
camera and shooting conditions.
One very accurate way to do this, if you are on windows, is to use the
curvemeister demo to generate a set of curves that accomodate your
particular camera. The procedure involves photographing the same scene with
your camera set for daylight and indoor lighting, then using Curvemeister to
"extract" a curve from the difference between the two images. This may all
be done using the curvemeister demo, saving curve files from the demo
version and use them in Photoshop to convert your images.