VLookup help...PLEASE

Thanks but it doesnt help. The case numbers (in column A) are in order but some are repeated several times and some are not. Only once does a date show up (in column B) for each particular case number. The dates are random. That is why I thought if on a seperate page I had the case numbers and the dates only once I could do vlookup and pull the correct date over depending on the case number.
I really do appreciate the help.
Katherine