Problem updating one spreadsheet with another

We use a huge 'master' spreadsheet with has move than 40,000 rows of data and goes to column CD currently. Because it is so large, we don't let the users have access to it and instead give them an update workbook where they can add changes that they make. It's 20 columns and each column matches one of the many on the master.

For instance, headings are:
Unique ID Manger Address CIN Policy Comment

So on the 'Updates' spreadsheet, we might see the Unique ID for the corresponding customer on line 12,453 on the Master workbook. And if we need to change the address at C12453, we have to manually pull it up. Every day we get approximately 400-450 changes to make and this is a tedious, time consuming process.

Is there a way to do this with VBA? It would have to be pretty simple, I am not good with this and used to get help from Tom Ogilvy at AllExperts (a GENIUS!) but it's now defunct.

Any ideas? Please don't recommend I look into Access, that is not a possibility.

Use Find method for example like explained in VBA inner help to search the cell ID …

I don't know what that refers to, VBA inner help. Is that a post on this forum or something within Excel? Elaborate a little, please, and I will look into Find.

The help on VBE side via its upper right textbox ! Or search on MSDN site …

As you can also use MATCH worksheet function …

Thank you, Marc.