Reconciling Multiple Tables of Data Efficiently

[EK923]

Update:
This post is no longer an accurate reflection of what I'm trying to do. Please click here to see the latest state of the issue.

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Hello! This is my first time posting to the forum, so I apologize if this is in the wrong place, or if I break any of the usual practice around these parts.

Here's the project I've got at work:

• There is an online database of clients that have contacted my company, a leasing agency, in the past calendar year. This database can be downloaded as an excel document ("Doc A").
• A separate company commissioned us to lease their properties.
• They gave us an excel document ("Doc B") containing all those who have leased units from them in 2012.
• Both documents contain thousands of entries, with fields for name, telephone, and contact number.
• I am supposed to look at Doc B and determine which of their current tenants found out about the property through us.
  Process right now:
  • Start with the first entry on Doc B.
  • Search for an identical entry in Doc A.
  • If there is a match: highlight the entry in Doc A. They found out about the property through us.
  • If there is no match: ignore the entry in Doc B. They found out about the property through someone else.
• Finally, I am supposed to submit a list of matches found in Doc A to my supervisor.

Here's a list of things I'd like to do:

• Find any macros, formulas, etc. to help automate any stage of this process.
  In particular:
  • Hide all empty rows and columns in the file. For some reason, the entries are each at least 15 cells apart when I open either document in excel.
  • Search for identical entries between two separate documents (or at least two separate sheets in the same document)
  • Gain results by searching for only a partial match (e.g. getting results with "johndoe@" vs. "johndoe@thisishislongemailaddress.com")
• Sort list into "highlighted" and "not highlighted" (descending order) once it is finished.

As ever, I'm on a tight schedule for this project. Does anyone have any help they could offer? I will give you all the positive vibes I can muster (which is a considerable amount).