HELP - calling all Excel Wizards! VLOOKUP and ...

Quick summary of my dilemma...
In my role of hr admin jockey, I have multiple worksheets to track:
1) Job orders that are open (Req Log) - (the Req # is the key field - no duplicates)
2) Candidates that have been submitted (Submittal Log) - (there may be multiple people attached to a single req, and/or a single person attached to multiple reqs - this is important for later on)
3) The details of any placements that have occured (Assignment Log)

In other places in the workbook, I have used to VLOOKUP to minimize duplicate entry of the same data on different worksheets, but this one has me stumped.

I want to use VLOOKUP to bring over the candidate's name and other details from the Submittal Log to the Assignment Log once a placement has been made, but due to the fact that there may be multiple submittals to the same req (as mentioned above), the VLOOKUP will not return the right value since there are multiple records that meet the lookup_value.

I need to find a way to cross-reference the VLOOKUP selection with another field (a field in which only the record associated with the placement has a "Yes" value in it) so that the function returns the appropriate data.

I know this is getting long-winded, but I figured you would need the details.

Any help would be greatly appreciated.

Thanks