Duplicates in lookup table

[tester1234]

I'm not sure if this is even going down the right track, but i've looked at using Index Match as well but cant wrap my head around it.

I have a spread sheet that has Title Nums "I" column, a lookup command "J" column, and a lookup table, "B:C". What I want is that the first instance in "I" gets the first instance of Reg Num, the second instance gets the the second, and so on. So for example J2 is correct here but J3 should be "1234". any help would be greatly appreciated, thanks.

 

[tester1234]

Solved using this method

Lookup the Second, the Third, or the Nth Value in Excel

In this tutorial, I will show you how to lookup the second, third, or Nth matching value in Excel. It shows two methods - helper columns & array formula

trumpexcel.com