Splitting Columns without generating new column

let
    Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("i45WMqqorFCK1QEzjCsqE5NMLUws9QyNTItzrBPTlGJjAQ==", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [Test = _t]),

    
    Extract = 
        Table.TransformColumns (
            Source,
            {
                "Test",
                ( ColumnValue ) =>
                    let
                        Split = 
                            Text.ToList ( ColumnValue ),
                        SelectNumbers = 
                            List.Select (
                                Split,
                                ( x ) => List.Contains ( { "0" .. "9" }, x )
                            ),
                        Combine = 
                            Text.Combine ( SelectNumbers ),
                        ToNumber = 
                            Number.From ( Combine )
                    in
                        ToNumber
            }
        ),
    ChangeType = 
        Table.TransformColumnTypes ( 
            Extract, 
            { "Test", Int64.Type } 
        )
in
    ChangeType