Update sheet - may be by using a macro

Hello,

I am trying to make a kind of template file which will be used by different users, most of them even more simple excel users than me :-) The user will usually work on a sheet, let's call it Master. The plan is that about once a month the users will import data from an external workbook to a sheet in their workbook, let's call it "Dataimport". Based on information in that sheet change some of the content in Master, both row and column information. Master and Dataimport will have the same unique id-information in column A. The update should behave like this:
- If there are any new id's (new rows) in Dataimport, Master should be updated with these new id-rows
- If an id in Master is not to be found in Dataimport, the row should be deleted from Master
- If the cell content in Master and Dataimport equals, the Master value should be kept (the users may add hyperlinks in the cell. For instance: The cell shows date for a contract written, and the hyperlink goes to the document)
- If the cell content in Master and Dataimport is different, the Dataimport should be copied to Master. (There will never be any hyperlinks in Dataimport.)

(I have made an example file, but I could not see how to upload it...)

I have tried different ways to solve this, but none of them will work 100% as I want them to. I would be very glad if someone "out there" could help me on the right track.