match in excel

[Bart]

How can I match 2 columns ?

a1 b1 a2 b2
c 2 d2
001 un801 lala un801
002 un802 kaka un802

My question is how can I match culomn b1 with b2, so that the information in
column a1 is copied to c2 or d2?

Thanks

 

[Otto Moehrbach]

Bart
Try that again. What constitutes "match"? What condition precipitates
the copying of data? What conditions or situations result in the
differentiation between Column C & D? HTH Otto

 

[Bart]

I already got the answer by the use of the formula VLOOKUP.

Sorry for the poor formulation of my question.