Linda,
I would take an image of just the color checker. Then one with the color check and each piece of art. And also make another image in "exactly" the same light of just the art.
Then you can use the color checker image to run the script. There are three versions, I am at the wrong computer to give you the link. (Tom Fors is the original developer, the one that seems to give me the best results is a version of Tom's script that has additional parameters.)
Since you are working with a computer without a calibrated monitor, most of this workflow will probably have to wait till you get home.
Running the script and inputing the results into camera raw is the first step.
Then when you open an image of the art with the color checker you can do a white balance by clicking the eye dropper on the second gray square. and then open the image in CS3.
I then open a selective color layer. It has options to select Red, Blue, Green, Yellow, Cyan, Magenta, white, midtone, black.
I start with black. With that selected place the curser over the black square on the color checker and notice the RGB readings in the info window.
There is a reference (again i will have to provide the link later) available that has Color Checker readings for the most widely used color spaces. Use the sliders (They are the complements of RGB) to adjust the RGB readings to match those in the reference.
When you are done, save the layer as a preset for that piece of art and then open the image without the color checker using same setting in Camera Raw you set for the previous image.
Then when it is opened in CS3 add a selective color layer and load the saved preset.
I have found, using this workflow and then converting the image to sRGB and saving for the web from CS3 that the resulting JPG prints a reasonable facsimile of the art on a standard printer without any color management. i.e. anyone can print a reasonably good image.
David
