I have a 99 Ford Taurus. I can not shift it using the column shifter, but can manually shift it through the engine compartment and I can drive it and I can shift it back into park with the column shifter when I am done. If it is a shift cable adjustment, would it be adjusted under the dash or??

Remove the cover to the column and check things out. Disconnect the negative battery cable first, just to be safe.

What is there to adjust on the steering column for this? Any help is gratefully appreciated.

Using your mechanical ability, you need to check the column shift mechanism out. Look for anything that doesn't appear right. Get an idea of how it functions. If nothing jumps out at you, then get a Haynes Manual or look online for how an adjustment is made. Unfortunately, I don't have any experience in this area.