This article demonstrates how to extract a small icon from an application.
function GetSmallIcon(const AFile : String) : THandle;
var
Info : TSHFileInfo;
InfoSize : Integer;
begin
InfoSize := SizeOf(TSHFileInfo);
FillChar(Info, InfoSize, 0);
SHGetFileInfo(PChar(AFile), 0, Info, InfoSize, SHGFI_ICON or SHGFI_SMALLICON);
Result := Info.hIcon;
end;