int total = ExtractIconEx("C:\\mirc\\mirc.exe",-1,NULL,NULL,0);
using ExtractIconEx you dont need an HINSTANCE argument
if you do need the icon (as in your second question) you can use the following
HICON icon;
ExtractIconEx("C:\\mirc\\mirc.exe,5,NULL,icon,1);
then send that to mirc
SendMessage(mWnd,WM_SETICON,ICON_SMALL,(LPARAM)icon);
swap the NULL and icon args in the ExtractIconEx and use ICON_BIG as wparam to set the large icon (alt+tab) for mirc. the 5 is the index (0 based) of the icon to extract.
as for the thrid question yes you can send the WM_COMMAND message directly to simlate menu item clicks. However you msut know the id of the menu item and theres nothing regulating these mirc can change them whimsically on every build if khaled so chose. He has been known to change classnames as well as child id's in the past so be carefull there.
