How hard is it to fix a hanging columella ??

The columella is made of cartilage. And it's the same cartilage as the cartilage that forms your tip. So you can't just raise the columella without possibly doing something bad (or good!) to the tip of the nose at the same time.See the short attached video for an example of elevating a drooping columella during a revision operation.If you're looking at having a revision, you should take a look at my "Web reference" link, just below this post. It has a good section on how to make sure that your revision surgeon is up to the task.

Without photos, it would be difficult to answer your question because a hanging columella can have a wide range of issues. My best advice is to consult with a board certified plastic surgeon who has many years of experience in revision rhinoplasty.  Phone consultations can be set up and, along with emailed photos, would probably provide you with a more concrete answer.