Compare Two Lists

I know how to do this in Excel using VB, but cannot get anything working in creator.

Basically, I have two lists in ZC, call them A and B. These are separate single column databases: List A is a vary long series of numbers while List B is very short. What I want to do is tag List A with any entries that match in List B. I'd add a new column (text field) to List A for the tags "matched".

I'm just about ready to pull these into Excel and do it with VB, but wanted the Zoho community to take a look first.

Thanks