This is somewhat of a d'oh! I'd forgotten:
1- In spreadsheet-eese, text  *IS* Tab delimited.
2- When in doubt, record a macro.

Looked good. The String ""'s don't appear in the test.txt file  I
just did. Almost a winner, but... Excel always saves a rectangular
area in ASCII formats. Shorter lines  are padded with trailing Tabs.
I suspect that'll gag the other application I'm trying to emulate. At
least I can still build my own strings w/Tabs without quotes.

After I get that, the converse - reading the file back in.

If I could just use something like the old file I/O commands
[Input,Write,Print], it'd be just fine. I have seen something like
that in VB context somewhere... Perhaps the same technique I use for
serial I/O will work for files, just need to figure out the way to get
to a file vs. port..