EXCEL - Set a cell's value based on a value in another worksheet

I have a spreadsheet with 2 worksheets and am trying to set a value on one worksheet based on a value in the other worksheet using an excel formula. An example follows:

Worksheet 1 (WS1) has three columns (1) WS1-ROWID, (2) WS1-EXTERNALID, (3) WS1-DESCRIPTION, and (4) WS1-QUANTITY
Worksheet 2 (WS2) has two columns (1) WS2-ROWID AND (2) WS2-EXTERNALID

There is a one to many relationship between the two worksheets. For every row in WS2 there are 1 or more rows in WS1
The worksheets are related by the WS1-EXTERNALID and the WS2-EXTERNALID

I am trying to populate WS1-ROWID in WS1 with the value found in the corresponding WS2-ROWID. So, if WS1-EXTERNALID = WS2-EXTERNALID, set WS1-ROWID = WS2-ROWID

I probably didn't explain that real well but I've also attached a sample spreadsheet that should describe what I am trying to do.

Any help will be greatly appreciated.
Who is Participating?

[Product update] Infrastructure Analysis Tool is now available with Business Accounts.Learn More

I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

KoenChange and Transition ManagerCommented:
is this what you need ?

write in Worksheet 1 , cell a2 : = index('worksheet 2'!$a$2:$a$5, match(b2,'worksheet 2'!$b$2:$b$5,0))
and copy down...

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
cbridgmanAuthor Commented:
Thanks Koen,

That is just what I was looking for.
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
Microsoft Excel

From novice to tech pro — start learning today.