How can I set the properties (via code I mean) of the find dilogue box to cause Dopus to find files where the search string i enter is matched against the file name OR the description?
If possible, the idea is to consider the Description field as a tag...so that Dopus looks in both File Name and File Description fields for a match.
You can do it using the Find panel in the advanced mode to define a filter.
You can save the filter so that you can quickly recall it after opening the Find panel, then type over the two search fields.
You can also bind the filter to a button, but you can't make it so that a button which uses a saved filter prompts you for what to search for. (Only simply filename searches can trigger a prompt like that at the moment.)