A day program? Sounds like what is commonly referred to as "out patient" rehab. Or rehab after work or etc.
What they can do is attempt to educate you on addiction and offer solutions to move forward. You will most likely be introduced to the 12 step model of recovery and urged to attend AA meetings. It is usually a mixed bag of people. Could be as few as three people to up to 8 or more. From young to old. The older are usually fighting alcohol addiction, the younger usually street drugs. Some are there voluntarily and some are there to keep the PO off their backs. Some are good and some are, well, not so good. It will give you an opportunity to interact with other addicts and see the similarities you have with them. Sometimes it can seem like a day care center, sometimes there is an active group of folks who wish to learn how to overcome addiction. Best I can offer.
Oh, and as for helping your sobriety, the only thing that will ensure that is your willingness to take is seriously and commit to not using.
I will never drink again and I will never change my mind.