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.
Sure Fit and other similar slipcovers will fit couches that are 83 to 96 inches long, a love seat cover will be for a 58 to 73 inch piece and a chair slipcover is for 32 to 43 inches. Also, measure the distance from the floor to the bottom of your sofa, as some covers have a ruffled or pleated skirt at the bottom.