Help with VB Script Compare and Update

Good Morning All,

1. Compare the sheet UPDATE and MASTER. If there are NEW values (based on ID column) then paste those to the end of the MASTER sheet. If there are items MISSING in UPDATE but are found in MASTER I want the ID value in MASTER to have an "x" put on the front of the value. IE - if the value in master was 1234 and the value is MISSING in UPDATE then the value in MASTER will now be "x1234".

Now the master should contain all new values and all old values will be preserved with an "x" in front of the original number.

2,. Now for those values where we added an "x" I want the values in the DASHBOARD sheet to be changed from 1234 to "x1234" so the INDEX lookup will find the new value.

I am attaching 2 files. One is ORIGINAL before the script runs. The second is UPDATE which is the desired result AFTER the script runs.