diff --git a/ADO2024/PI4/Helper-2024-12-12.cs b/ADO2024/PI4/Helper-2024-12-12.cs
new file mode 100644
index 0000000..4e43f1d
--- /dev/null
+++ b/ADO2024/PI4/Helper-2024-12-12.cs
@@ -0,0 +1,35 @@
+using Microsoft.Extensions.Logging;
+
+namespace File_Folder_Helper.ADO2024.PI4;
+
+internal static partial class Helper20241212
+{
+
+    internal static void Rename(ILogger<Worker> logger, List<string> args)
+    {
+        string newFile;
+        string fileName;
+        string newFileName;
+        string directoryName;
+        string searchPattern = args[2];
+        string[] searchPatterns = args[3].Split('|');
+        string sourceDirectory = Path.GetFullPath(args[0]);
+        string[] files = Directory.GetFiles(sourceDirectory, searchPattern, SearchOption.AllDirectories);
+        if (files.Length == 0)
+            logger.LogError("No files found in {sourceDirectory} with search pattern {searchPattern}", sourceDirectory, searchPattern);
+        foreach (string file in files)
+        {
+            fileName = Path.GetFileName(file);
+            directoryName = Path.GetDirectoryName(file) ?? throw new Exception();
+            newFileName = fileName;
+            foreach (string pattern in searchPatterns)
+                newFileName = newFileName.Replace(pattern, "");
+            newFile = Path.Combine(directoryName, newFileName);
+            if (File.Exists(newFile))
+                logger.LogError("File {newFile} already exists", newFile);
+            else
+                File.Move(file, newFile);
+        }
+    }
+
+}
\ No newline at end of file
diff --git a/Day/HelperDay.cs b/Day/HelperDay.cs
index ad06c53..38ebeaa 100644
--- a/Day/HelperDay.cs
+++ b/Day/HelperDay.cs
@@ -121,6 +121,8 @@ internal static class HelperDay
             ADO2024.PI4.Helper20241115.GetComplete(logger, args);
         else if (args[1] == "Day-Helper-2024-12-04")
             ADO2024.PI4.Helper20241204.ConvertToUTF8(logger, args);
+        else if (args[1] == "Day-Helper-2024-12-12")
+            ADO2024.PI4.Helper20241212.Rename(logger, args);
         else
             throw new Exception(appSettings.Company);
     }