Hello as i was bored of having that useless CPU at the highest with an i7 i started to search and found it.
It's close to a Sleep Call, i was originaly searching for a USER32.GetMessageA and found it a few line bellow.
You can patch it here: "D2Win.dll"+18A5F (change it to JNL (0x7D).
At the first render "pass" on the main menu you will have bullsh** CPU Use but a second later it all return to 0-1% of CPU Usage, work fine on win7 as i'm still on win7, would be good if Whist could agree that it is the correct offset (maybe it is a different "fix") but it work very well and there are no problem exiting the game as well so huh i made a post for the people that want to make their own patch with ollydbg.
Cya !