cd "c:\documents and settings\account\desktop\arc2"
mzscheme -m -f "as.scm"
the cd seems to be necessary. my guess is mzscheme takes note of the directory you launch things from, and relative file paths in the arc implementation are considered relative to where you launched the command, not relative to the folder as.scm is in
though i don't use a batch file anymore. not after i implemented a nice automated paste-this-code-from-Vim-to-the-REPL AutoHotkey script