Rename multiple column names along with changing their column numbers to Letters

Hi Anonymous ,

your formula won't work in a "Table.TransformColumnNames"-formula. You have to use Table.RenameColumns instead like so:

let
    Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("i45WMlTSUTICYmMgNlGKjQUA", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type text) meta [Serialized.Text = true]) in type table [ID = _t, Agg = _t, Cluster1 = _t, Cluster2 = _t]),
    Custom1 = 
        Table.RenameColumns(
            Source, 
            List.Zip(
                {
                    Table.ColumnNames(Source), 
                    List.Transform(
                        List.ReplaceValue(
                            List.FindText(
                                Table.ColumnNames(Source),
                                ""),
                            "Cluster",
                            "TC",
                            Replacer.ReplaceText), 
                        each if Text.Contains(_,"TC") 
                                then Text.Replace("_", "_","TC " & Character.FromNumber(Number.FromText(Text.Middle(_,2))+64)) 
                                else _ )
                } ))
in
    Custom1