Index and Match-search across mutliple columns

Hi,

I don't know if this is possible but I need a way to search across mutliple columns and return a value related to that number...let me explain...

On one sheet I currently have a row of ids, next to a row of names.
On my main worksheet a person will enter in an id and by using the formula:
IF(B9="","",IF(ISNA(VLOOKUP(B9,ValidationLists!T:U,2,FALSE)),"Unknown",VLOOKUP(B9,ValidationLists!T:U,2,FALSE)))
A name will automatically be populated in the cell next to which the id is entered.

This has worked just fine but now my list of ids and names is longer than 65,536 rows that excel allows. So I was wondering if there is a way to have my data in 4 columns - 2 columns with a list of ids and 2 with a list of names and then to have a formula that will search across both rows of ids from which to pull the correct name??

If anyone has any recommendations or suggestions I would very much appreciate it!

Thanks!

Thank you so much! That worked perfectly! I am new to working with formulas in Excel and I was going crazy trying to figure out a way to do it!

Thanks again!