Depending on which game your trying to edit. Either RA2 or YR you need to get XCC mIxer and XCC Mix Editor. Also i would advise you download Deezires INI Editing Guide its an indisposable asset.
Get XCC mixer & XCC Mix Editor here:
http://xccu.sourceforge.net/
and Modding FAQ guide here:
http://ra2faq.gamerzvilleuk.co.uk/