I’m trying to extract a part of a string field [Short description] and place it in a new custom field in Power BI Query [NewDesc].

For example, if the [Shoer description] field is:

“SNOW – 1234 – My description here”

I would like the [NewDesc] field to return everything after the 4th space, ie:

“My description here”

My query in the editor is:

= Table.AddColumn(#"Reordered Columns1", "NewDesc", each 
 if Text.StartsWith([Short description], "Sentinel") then 
  let
      // Split the text by spaces
      SplitText = Text.Split([Short description], " "),
      // Find the index of the 4th space
      FourthSpaceIndex = List.PositionOf(SplitText, "", 4) - 1,
      // Extract the text after the 4th space
      ExtractedText = Text.Middle([Short description], FourthSpaceIndex + 2)
  in
      ExtractedText
else 
  [Short description]
)

I’ve tried number of ways, but for this, the error is:

Expression.Error: We cannot apply operator - to types List and Number.
Details:
  Operator=-
  Left=[List]
  Right=1

Can anyone help correct my query please?

Thanks, Mark