I never played WC3's expansion, but were you able to keep your win achievements from games played on the original multiplayer?

You get icons + stats (win/loss percentage) for battle.net games (Ladder matches) only. It works a bit similar to Sc2.

If you get 25, 150, 350, 750, and 1500 wins for a single race in ladder you get a new icon. You also have the win percentage in your profile per race and overall.