Quick and dirty mit AppleScript

Code in den Script Editor kopieren und starten.
Dann die Spaltennummer eingeben. Alle negativen Zahlen (kein Text) werden positiv.

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repeat
  try
    set columnString to text returned of (display dialog "Bitte Spaltennummer eingeben (A=1)" default answer "1")
    set columnNumber to columnString as integer
    exit repeat
  end try
end repeat
tell application "Numbers"
  tell table 1 of sheet 1 of document 1
    repeat with i from 1 to row count
      tell column columnNumber
        set theValue to value of cell i
        if class of theValue is real and theValue < 0 then set value of cell i to -(theValue)
      end tell
    end repeat
  end tell
end tell