[Wine] Smth. about "Icon=" option in .desktop files created by WINE

[justadude]

When I install some Win32 application using WINE, it creates associated menu item file for it, located at ~/.local/share/applications/wine/Programs/***Program title***/***Program shortcut.desktop***. Well, inside this file I see option named "Icon", where path to some icon is set. Sometimes this path points to some PNG image file, but sometimes it points to something I don't have a clue about, like that one: "Icon=4e90_flv2mp3.0". Could anybody tell a newbie what does that means? And, how does WINE exctract icons from EXE files and converts them into PNG? Could I somehow do it by myself, if a program I install has no installation file, so I have to manege it manually?