21} Do you have pointers to additional script material and tips?

Yes, some. But since the links to outside material may (or may not) be transient and volatile in nature I will rather point to a web page of mine carrying references to programming material. Link directly to https://www.salminet.fi/http/tshttpprog.html#cmdscript

Where do I find a detailed command-line reference? (The steps below pertain to XP only)
  Left-click "start" in the Taskbar
   Click "Help and support"
    Enter "Command-line reference" into the Search window
     Two suggested topics should appear
      Choose from "Overviews, Articles and Tutorials"
       Click "Add to Favorites" to quickly locate the item in the future

Here are some other useful NT/2000/XP CMD.EXE command line scripts programming pointers and links related to this FAQ

  Windows XP own command-line reference also: hh C:\WINDOWS\Help\ntcmds.chm
  The location may vary depending your particular configuration.
  If so, try the included WHEREIS.CMD script.
  On post-XP systems you have to copy ntcmds.chm from an old PC with Windows XP
  Or see Command-line reference A-Z

Update: Apply:
  hh WinCmdRef.chm from a Microsoft download page

In newgroups e.g.
  How do I control echoing in batch files? (Walter Briscoe)
  Google Groups Nov 28 2003, 9:00 pm

More generally:
  Miscellaneous questions, information and comments about Timo's
  programs etc. https://www.salminet.fi/homepage.html#faq

Newsgroups (here in the Google format) including
  alt.msdos.batch.nt
  microsoft.public.win2000.cmdprompt.admin
For more on newsgroups, see e.g.
  https://app.box.com/s/xi0lf4uiyus4ht5j1i86coxz4jxop4a6