I do not know about codekit syntax, but if all you need is the prepend feature, then take a look at https://github.com/miensol/grunt-concat-in-order, and specifically the filebased approach. You could customize the syntax to extract your codekit prepend syntax or replace that to something like @depend used in the example.
(for a cross platform example check out my fork, it has a windows safe example, using path.normalize)