Technically, you don't really need another program, but there are others on the Cool Running website that might be particularly helpful if you are aiming to build to something specific.
A quick bit of advice from one relatively new runner to another
- build your distance before you work on speed; the speed will come, and you'll reduce the risk of stress and over-training injuries (and by over-training, I mean speed, not distance) Even distance, it is a good rule of thumb to only add 10% per week or couple of weeks.
Good luck - and way to go on (almost!) completing the C25K!!