Large Data Replacement

Hi

I have 100,000 records. Data in columns AW and AX.. NUMERIC DATA

Not every row in AX has data in it

I want to run from top to bottom and where there is a record in AX, check if it appears anywhere in AW and where it does, replace the AW record with the AW record attaching to the record being checked

example below. As 113 is in the 2nd column and also in the 1st, anywhere it is in c1, I want it replaced with 128 as that is the corresponding record in C1 where 113 was found in c2

C1 C2
113
114 190
128 113
189 201