Carpenter to patch timber overlying Aircon hole

Have acquired an old condo unit where the Aircon hole exterior is just planking (circled). Am looking for a carpenter to patch it up (lay down some more boards over planking and waterproof with sealant) to avoid leakage problems while we try to tidy up and renovate the inside. I do not intend to change the Aircon units until all the rest of the cleanup and Reno is done which will be many months down the line. Please help to recommend or come forward if you can do the job. I have approached several handyman firms but they all say they don't handle this kind of thing.