Update sheet by macro

Once a month I want to import data from an external workbook to my excel sheet (let's call it "Master") and change some of the content in Master, both row and column information. I guess the dataimport is easiest done by pasting new data to a separate sheet (let's call it "Dataimport"). 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...)