You can appeal to the Court of Session against a decision made by the Commissioner, but only if you do not think he has applied the law correctly - not because you disagree with the Commissioner's view of the case.
A point of law could be, for example, if you think the Commissioner adopted the wrong definition of a legal term, or misinterpreted his powers.
If you appeal to the Commissioner and he doesn't reach a decision on your appeal after four months, or other reasonable period, you could ask the Court of Session for a judicial review.
If you are thinking about an appeal to the courts or a judicial review, you should get legal advice.