Look in your yellow pages under Janitorial Equipment & Supplies. Any of the companies there that sell carpet cleaning chemicals will also sell professional "spotting" solutions, which is a fancy way of saying "stain remover".
You can buy spotting solutions for blood, urine and feces, vomit, wine, coffee and tea, and ink and toner. You can buy a kit containing anywhere from 8 to 22 different spotting solutions, or you can buy the individual spotting solutions, which is what the pros do when they run out of one in their kit.
Buy the spotting solution and apply it according to the directions to your carpet.
Use a wet/dry vaccuum cleaner to suck the soiled spotting solution out of your carpet. Just turn the vaccuum cleaner on and press the suction hose directly against the carpet pile. The air flow through the carpet pile will carry the soiled spotting solution out of the carpet as a mist. Repeat as necessary to get the stain out completely. Then apply clean rinse water and suck that outta the carpet too. Allow to dry and evaluate results.
People also say that the alcohol in hair sprays will dissolve alcohol based inks, so you can try that if you have some hair spray on hand. However, by buying the same spotting solutions that the professional carpet cleaning contractors in your area buy, and using a wet/dry vaccuum cleaner as a poor man's carpet shampooer, you can do as good a job removing the stain as any of the professional carpet cleaners in your area would do.