Filtering unwanted cells

I'm trying to filter out unwanted data from a spreadsheet.

I have two columns, (A) contains a series of numbers and this is the search criteria. Column (B) contains the data.

Example:

A
7887765
4344555
2233455
8386375
3647364
3847387

B
7875895
3847387
8386375
5345344
3465356
9887645
5767655
8386375
3847387

8386375 & 3847387 appears in column A and twice in B


I want Excel to filter out any unique numbers in column B which don't appear in column A.

Is this possible?

I'm using Excel 2007.

Thanks

Gav