Could you perhaps paste the data to another document (temporarily) and then add a table to the original document?

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Stefan Blom
Microsoft Word MVP

Microsoft 365 apps for business
Windows 11 Professional

If you put the insertion point at the top left of the first column and hit enter enough times that column will begin to emerge on top of the second. Then cut and paste or drag the second into where the first was. You'll have to delete the appropriate number of carriage returns.

Sorry, but I don't see how that would help the original poster.

__________________
Stefan Blom
Microsoft Word MVP

Microsoft 365 apps for business
Windows 11 Professional

My reasoning was that if you convert two-column text to one column, then one column sits on top of another, as it were. Then simply select and drag the bottom half of the column to the top and convert it back to two columns. It works for me, unless I've not picked up the OP's real problem.

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My 'pseudo-columns' are Tab-separated text.
I pasted it into Word. Converted to Table.
Using "Alt' key, cut and pasted the left column to the right of the Right column.
SO far so good, but at FINAL step it failed: copy/paste to a .txt file
put right column BELOW the left one. Not what I needed.

2nd maneuver: Move 2 columns to excel; copy/paste to .txt file.
Worked, but .... so labor intensive !

PS. In Original text, one column can not be copied - even with 'Alt' key.

PPS. Seems like I have to learn how to write a MACRO.
Is it possible ?

Thank you all for the help.