Read as need, how to read first 256 bytes from online large file without downloading?

I need to read just first 256 B from large file, from mapped WebDAV drive.

I open file with

h_second = CreateFileA(second_server, GENERIC_READ, FILE_SHARE_READ, NULL, OPEN_EXISTING, FILE_FLAG_SEQUENTIAL_SCAN, NULL);

but it first downloads whole file, and after that can I read it. And I want something, that downloads just a small part of file and I read that.

Can anyone help me?