Lookup & Return Adjacent Value From Left

I have two worksheets. The first one contains 500 rows:

Column A - Company Name
Column J - Formula that calculates a 'company score' based on other data in columns B-H
Column K - Number of directors

The second worksheet contains over 3000 rows:

Column A - Name
Column B - Company
Column C - Designation

I want to caculate a score for each person (from worksheet 2) that does the following:

Personal Score = ('Company Score' / No. of directors) * Designation Weighting

Where Designation Weighting (numerical value) is determined by Designation (text). There are 10 different and mutually exclusive types of text in the Designation column.

My problem is compounded by the fact that each person (in worksheet 2) can be directors on several companies. The Personal Score that I want to calculate needs to recognise which different companies they are directors of and sum the scores derived from each company.