Need Help with Replace Value

Hello Alice_Cooper 
I used this method to create the custom table.
BULK Replace Values in Power BI / Power Query - YouTube

Basically it involves your main query table, seconday table (TranslationsTable), custom function.

let
    Source = #table(
        type table [
            OldText = text,
            NewText = text
        ],
        {
            {"SECURE", "999"},
            {"D", "4"},
            {"/", ""},
            {"C", "3"}
        }
    )
in
    Source

(x as text) as text =>
  let
    maxIterations = Table.RowCount(TranslationTable), 
    Iterations = List.Generate(
      () => [
        Result = Text.Replace(
          x, 
          TranslationTable[OldText]{0}, 
          TranslationTable[NewText]{0}
        ), 
        Counter = 0
      ], 
      each [Counter] < maxIterations, 
      each [
        Result = Text.Replace(
          [Result], 
          TranslationTable[OldText]{Counter}, 
          TranslationTable[NewText]{Counter}
        ), 
        Counter = [Counter] + 1
      ], 
      each [Result]
    ), 
    output = Iterations{maxIterations - 1}
  in
    output

This method/approach will help you resolve your query.
Also, please view the video if possible to understand better.

Thank youu.
If my answer helps you, please mark it as solution.