Equivalent to autocomplete

Using Calc when entering data into a cell the system will attempt to autocomplete if matches are found above or below the row in use.

However I need the same capability instead for rows. So data being entered into a cell will look left, or right, to find possible matches.

Is there a hidden file where the default columns can be changed to rows?

If you can live with a drop list instead of autofill, it is trivial:

  1. Mark an entire row by clicking on the row number. Here we’ll say 1:1 as an example
  2. Click menu item Data>Validity…
  3. Click Criteria tab (if not there already)
  4. For Allow select Cell Range
  5. Select Sort Entries Ascending
  6. Set Source to the row you selected. Here it would be 1:1
  7. Select Input Help tab
  8. Uncheck Show Input Help
  9. Select Error Alert tab
  10. Uncheck Show Error Message
  11. Select Action as Information
  12. Press Ok button

If you copy the row down it will move the source cells to be the new row, which is almost certainly what you want.

Row Validation.ods (10.6 KB)

Replying to all. Using validation as a drop down list only, not requiring autofill looks promising. I’ve got to learn some ins and outs of this process. Trial and error so far suggests editing that list cancels out the selected cell range. Might be at my end. More to practice and learn.

Get some old Excel book and learn about relative, absolute and mixed references.

Or start with Addresses and References, Absolute and Relative .

I just read your comment about "cancels out the selected cell range. Go back and try following the step-by-step again. It sounds like you might be missing 4.

https://forum.openoffice.org/en/forum/download/file.php?id=333 demonstrates how to use the validation feature with formula expressions. Formula expressions include mixed references.

That appears to still be using columns, I need across rows. My next column in use is HH. Need to have entries look all the way back to column A.

Validation formulas work with coluns and rows. Your data layout seems to be catastrophic, which makes things unmanagable.
Try validation with the following settings:
Allow: “Cell Range”
Source:: $A_:HG_
where _ is the row number of the active cell.
80907.ods (12.2 KB)