Yes, is possible.
If you check character by character inside a string, you can convert the characters to uppercase with this:
http://forum.mikrotik.com/t/i-did-it-script-to-compute-unix-time/68576/18
The script can be adapted for replace for example space with _ but at the time I write do not have the time.
If you keep this post up on next days someone can help you, or I can find the time to write the script.