yup, that should do it.
btw, under the advanced editor (button that says "Go Advanced") you can wrap code tags around, well, code. ( # button)
Code:
Directory("\Windows"):-Directory("newDirToCreate")
EDIT oh, just realized Sailrace might just be making a sd config for flashing all the great roms available here.
try this
Code:
<characteristic type="FileOperation">
<characteristic type="\My Documents\newDirToCreate" translation="install">
<characteristic type="MakeDir" />
</characteristic>
</characteristic>