How to find and move a value based on multiple criteria
 

I have a very large spreadsheet consisting of columns with first names, last
names, ID numbers, and other data. I would like to search and copy ID#'s
associated with names to another sheet, using last names and first names.
For example:
jon smith 1234
mary jones 5678
dave wilson 3456
dave smith 7890

I woud like to find and copy the ID#'s, but as you can see, people might
have the same last name. I used VLOOKUP("last name","range for names from
source sheet",3,FALSE), and get what I need ONLY for those with discreet last
names. When there are more than 1 results with the same last name, I get the
ID # of the first one in the list.