It can depend if its a single file or folder wiki. I do not have the answer but you can pass a search string on a uri to search once the wiki is loaded.
Someone has built a method to search wikis so do a little research in this forum.
You could generate an index and import and search that.
If you built a smart app that understood tiddlywiki files or folders you could find a string in such files and determine a way to extract the tiddler link or content. Windows can search html files
Just some thoughts but more help could come if you explain what you want to do rather than the method you think you need to use.
Regards
Tony