can't get IItemStack from String

[Tcll]

after trying, searching, and pondering various ways to get an item from a string, I've finally come to the conclusion it was impossible.

I have a script that operates on Magicalcrops, reconfiguring the recipes by storing the various seed/essence names in a string-list for easy maintenance:

var names = [ "Osmium", "Copper", ... ] as string;

and iterating over the list to make and print the changes:

for name in names {
    print('changing recipe for '+name+'Essence and registering '+name+'Seeds with oreDict seedsMagical')
}

but there doesn't seem to be any way to do the magic done in ItemBracketHandler.getItem(), nor any way to access it.