How to handle different encodings for Search URL and Server Response?

Hi, I am writing a Web Source script for a Japanese site that uses EUC-JP encoding. I am facing an "encoding mismatch" issue between the search request and the response:

If I set [Encoding]=euc-jp: The search fails because the query string is incorrectly converted, leading to corrupted characters in the Search URL.

If I set [Encoding]=url-utf-8: The search works perfectly, but Mp3tag then expects the returned HTML to be UTF-8 as well. Since the site returns EUC-JP, the resulting tags in Mp3tag are all garbled (mojibake).

Is there a way to specify url-utf-8 for the request while forcing the parser to interpret the response as euc-jp? If not, what is the recommended way to handle sites that don't use UTF-8 without using an external proxy?