Legal Question in Criminal Law in California

Some orders on motions are appealable, but most aren't. Since you haven't said what type of motion this was, that's the best I can do.

Sure, you can possibly appeal or seek a Writ as appropriate, if you have good legal cause to do so, and if you are timely in doing so, and if you are able to properly prepare effective pleadings to do so or are willing to hire counsel who can. Asking about 'title and caption' conveys that you are not familiar with the procedures, notices, and pleadings required, so I suggest you consult with someone for legal help. You only get one 'shot' at this, so it has to be right the first time.