Converting icons

Is there a program that can change my folder icon that keep saving in 24 bit that will allow me to convert them to 32 bit without loosing being transparent

i used to use aicon (hxxp://cidoc.iuav.it/~silvio/aicon_site/aicon.html) to create personalized folder icons, but you can use IcoFX to do the same.

thanks will look at them both