VLOOKUP on non-unique values

[Richard]

I have created a userform in VB which gives a drop down of
current projects. the prokect name is then inserted into a
cell, and the other cells filled in using vlookups on a
large spreadsheet of information relating to these
projects. There are multple units per project which do
have unique numbers but are not meaningful enough to use
as a search key. I would like to be able to search
on 'client' for which there may be several entries. How do
i get Excel to return the data for all the entries
relating to each unit for the client.

I apologise as i don't have my clear english head on at
the moment, but can explain further if necessary.

Thanks in advance

Richard