In addition to Joerg's comment; if your program path is being input by a user, then you "may" need to use a double backslash:
c:\\cscript.exe
BTW, is cscript.exe really in the root of c:? That command is generally in the Windows PATH so you shouldn't need to specify the path in your command. If you specify c:\cscript.exe , then that forces windows to look ONLY in the C:\ folder, not where the command is really found.