diff --git a/src/Calculator.Shared/Common/LocalizationStringUtil.cs b/src/Calculator.Shared/Common/LocalizationStringUtil.cs
index 61053fed..6f39a640 100644
--- a/src/Calculator.Shared/Common/LocalizationStringUtil.cs
+++ b/src/Calculator.Shared/Common/LocalizationStringUtil.cs
@@ -1,55 +1,82 @@
 // Copyright (c) Microsoft Corporation. All rights reserved.
 // Licensed under the MIT License.
 
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Text.RegularExpressions;
+
 namespace CalculatorApp
 {
-    namespace Common
-    {
-        public static class LocalizationStringUtil
-        {
-            public static string GetLocalizedString(string pMessage, params object[] args)
-            {
-                // UNO TODO
+	namespace Common
+	{
+		public static class LocalizationStringUtil
+		{
+			public static string GetLocalizedString(string pMessage, params object[] args)
+			{
+				var stringBuilder = new StringBuilder(pMessage);
 
-                //string returnString = "";
-                //const uint length = 1024;
-                //std.unique_ptr<wchar_t[]> spBuffer = std.unique_ptr<wchar_t[]>(new wchar_t[length]);
-                //va_list args = NULL;
-                //va_start(args, pMessage);
-                //int fmtReturnVal = FormatMessage(FORMAT_MESSAGE_FROM_STRING, pMessage, 0, 0, spBuffer.get(), length, &args);
-                //va_end(args);
+				// This will capture all %<number> strings
+				var matches = Regex
+					.Matches(pMessage, @"%(\d+)")
+					.AsEnumerable()
+					.OrderBy(str => str.Value.Replace("%", ""));
 
-                //if (fmtReturnVal != 0)
-                //{
-                //    returnString = spBuffer.get();
-                //}
+				// If our starting index begin at 1, we will decrease all of them in order to use string.Format
+				if (matches.FirstOrDefault()?.Value == "%1")
+				{
+					var addedCharacterFromOriginal = 0;
 
-                //return returnString;
+					foreach (var match in matches)
+					{
+						if(int.TryParse(match.Value.Replace("%", ""), out var argumentIndex))
+						{
+							stringBuilder.Remove(match.Index + addedCharacterFromOriginal, match.Length);
+							stringBuilder.Insert(match.Index + addedCharacterFromOriginal, "{" + (argumentIndex - 1).ToString() + "}");
+							// Since we are replace %<number> by {<number>}, we will add one character for each iteration
+							// so we need to consider that
+							addedCharacterFromOriginal++;
+						}
+					}
+				}
 
-                return $"[{pMessage}]";
-            }
+				return $"{string.Format(stringBuilder.ToString(), args)}";
+			}
 
-            public static string GetLocalizedNarratorAnnouncement(string resourceKey, string formatVariable, params object[] args)
-            {
-                EnsureInitialization(resourceKey, formatVariable);
-                return GetLocalizedString(formatVariable, args);
-            }
+			public static string GetLocalizedNarratorAnnouncement(string resourceKey, string formatVariable, params object[] args)
+			{
+				EnsureInitialization(resourceKey, formatVariable);
+				return GetLocalizedString(formatVariable, args);
+			}
 
-            static void EnsureInitialization(string resourceKey, string formatVariable)
-            {
-                if (resourceKey == null || string.IsNullOrEmpty(resourceKey))
-                {
-                    return;
-                }
+			static void EnsureInitialization(string resourceKey, string formatVariable)
+			{
+				if (resourceKey == null || string.IsNullOrEmpty(resourceKey))
+				{
+					return;
+				}
 
-                // If the formatVariable already has a value, we don't need to set it again. Simply return.
-                if (formatVariable != null && !string.IsNullOrEmpty(formatVariable))
-                {
-                    return;
-                }
+				// If the formatVariable already has a value, we don't need to set it again. Simply return.
+				if (formatVariable != null && !string.IsNullOrEmpty(formatVariable))
+				{
+					return;
+				}
 
-                formatVariable = AppResourceProvider.GetInstance().GetResourceString(resourceKey);
-            }
-        }
-    }
+				formatVariable = AppResourceProvider.GetInstance().GetResourceString(resourceKey);
+			}
+
+			static IEnumerable<Match> AsEnumerable(this MatchCollection source)
+			{
+				var enumerator = source.GetEnumerator();
+				var returnedEnum = new List<Match>();
+
+				while (enumerator.MoveNext())
+				{
+					returnedEnum.Add((Match)enumerator.Current);
+				}
+
+				return returnedEnum;
+			}
+		}
+	}
 }