You can use ^ and %, but must enter them in the _Alphanumeric variable twice as ^^ or %%. However, if you want to use the result (_RndAlphaNum) later in the batch file (other than Echoing to the screen), they might require special handling. You can even use a space, as long as it's not the last character in the string.
23 inches (59cm) is the minimum distance required for a chair behind a desk. This would fit a modest sized chair. For more comfort and to accommodate a bigger office chair increase the chair clearance to 30 inches (76cm). Office Chair tips. Swivel chairs make it easier to get in and out from behind your desk, especially if the space is a bit tight.
Chair rail is usually a smaller detail molding. Most chair rail ranges from 1 1/2 to 3 inches. Typically chair rail is smaller than door and window casing, and about 1/2 the size of the crown or baseboard. It tends to be slightly thicker than the baseboard or casing, to hold chair tops out away from the wall.