My company is switching from Microsoft Office to Google Docs, I have this (several) code I want to use in Google Spreadsheets but I have no idea on how to do that.
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This is currently impossible in google app script as there is neither worksheet selection change event nor selection change event in spreadsheet services. List of Google Spreadsheet events are Here.
But we have time driven triggers in GAS, through this you will be able to run a function at some particular time. In your case lets say morning 12AM. You have to write a function which will run at 12AM to go through all the sheets and then format Cells(Target.Row, 1) and Cells(Target.Row, 2) on to the format which you like.
Definitely you have to restructure your current spreadsheet... Welcome to Google App Scripting.