How Can I Use A Combination Of INDEX/MATCH And IFERROR Functions In Excel To Create A Dynamic Lookup That Returns A Value From A Separate Sheet Based On A Specific Criteria, And If The Criteria Is Not Met, Returns A Custom Error Message That Is Automatically Translated To The User's Preferred Language Using A Lookup Table?

To create a dynamic lookup in Excel that returns a value from another sheet based on specific criteria and provides a translated error message using INDEX/MATCH and IFERROR, follow these steps:

Step-by-Step Solution:

1. Set Up Your Data:

   • Data Sheet: Organize your data in a table with headers. For example, if you're looking up prices by product ID, have columns like ProductID and Price.
   • Translations Sheet: Create a table for error messages with columns for LanguageCode (e.g., "EN", "FR") and Translation (e.g., "Product not found", "Produit non trouvé").

2. Determine the User's Language:

   • Have a cell where the user can select their preferred language, such as cell A1. Use a dropdown list to ensure only valid language codes are entered.

3. Create Named Ranges (Optional):

   • Named ranges can make your formula more readable. Define ranges for your data and translations, e.g., DataRange for your data table and TranslationsRange for your translations.

4. Construct the Formula:

   • Use the INDEX and MATCH functions to perform the lookup.
   • Use IFERROR to handle cases where the lookup value isn't found and return a translated error message.

   Formula:

   =IFERROR(
     INDEX(DataRange[Price], MATCH(lookup_value, DataRange[ProductID], 0)),
     INDEX(TranslationsRange[Translation], MATCH(user_language, TranslationsRange[LanguageCode], 0))
   )
   

   • lookup_value: The value you're searching for (e.g., A2).
   • user_language: The cell containing the selected language code (e.g., A1).

5. Handle Language Lookup Errors:

   • Ensure the language code exists in your translations table. If not, you might add another IFERROR or a default message.

6. Test the Formula:

   • Enter a valid lookup_value to ensure it returns the correct data.
   • Enter an invalid lookup_value to see if the translated error message appears.

Example:

Suppose you have:

• Data Sheet:

  ProductID	Price
  101	100
  102	200

• Translations Sheet:

  LanguageCode	Translation
  EN	Product not found
  FR	Produit non trouvé

• User Language Selection: Cell A1 contains "EN" or "FR".

Formula in Lookup Cell:

=IFERROR(
  INDEX(Data[Price], MATCH(A2, Data[ProductID], 0)),
  INDEX(Translations[M][Translation], MATCH(A1, Translations[M][LanguageCode], 0))
)

• Lookup Value: A2 contains the product ID to look up.
• Result: If the product ID exists, returns the price; otherwise, returns the translated error message based on the language in A1.

Notes:

• Ensure all ranges are correctly referenced, especially if using multiple sheets.
• Consider using table structures for clarity and dynamic array handling.
• Test edge cases, such as when both the data and language lookups fail, to ensure robust error handling.

This approach provides a flexible and user-friendly lookup system with multilingual support.