There is no such command in batch files, at least not as far as I know.
Please give me a little more information:
(1) Do you want to do the case changes during runtime? What this means is that do you want to keep the file as is, but only display it in capitals when you run the file?
(2) Do you want to edit the file and change everything to capitals and then run the file?
For #1, I doubt you will find a solution, but for #2, there are several decent freeware editors available that can transform case for you, for example conTEXT. You can find it at:
http://www.fixedsys.com/context/Regards,
FolkLore