Retrieving part of the page body

Is there a way to retrieve only part of a page? I need to access a certain number of characters after the开发者_如何学C sexdecillionth character, and I know that it is possible. I can't request the page, because it returns response body too large. What should I do?

The platform and language don't matter to me, because I can access them all.

Retrieve it from what?

Generally speaking, you'll need to open an HTTP connection and use the Range: header to request the start location of the page download. I don't know that every web server supports it, though, so your mileage may vary.