How to limit crawls to English only pages?

Is there a way to have yacy crawl index only English language pages?

/CrawlStartExpert.html
Must-Match List for Country Codes

Forgive me but I am new to this. I find the file in htroot, but it is a big script and I do not understand
where I specify a country code.

localhost:8090/CrawlStartExpert.html

Though it seems to be based on the IP address country of the website? maybe it will not work.
Let us know.