LibreOffice Calc - Change values/cells from list

We often export and import csv data and have to change/add values/cells manually from a list of names or emails into our main-list. This often wastes a hugh amount of time, if the list is in the hundreds or thousands.

My question, is there a way or extension where you can explain LibreCalc to do stuff (like change color, add value to collumn) by a list of names/countrys/mails as source?

Mail-List example as source:

    info@company.com
    example@googlemail.com
    strangename@strangerdomain.com

Result:

    Search for entry in main-list.
    Add value "ok" into that collumn R.

If there is a well defined range containing the already collected a) names b) countries c) email-addresses you can, of course, decide if a proposed new entry would be a doublette. c) For email-addresses with their strict syntax this will work flawlessly. a) As for names it’s a question of precision: there are often variants because of mulish behaviour by different sources of the information. b) Countries in the middle so far.

c) again: Let’s assume you have a Sheet ‘Contacts’ where column E does exclusively contain email-addresses (not the hyperlink containing “mailto:”) and it is designed for up to 10000 entries in rows 11 through 10010. The newly imported mail-address may be “info@company.com” and placed in cell A77 of another (import-) sheet. If MATCH($A77;$Contacts.$E$11:$E$10010;0), best placed in an adjacent cell of the same row, does return a number (no error value or indicator) then the entry already is present under the index (relative to start of range) returned by the expression. Of course you will fill down the formula for as many rows you need (3 for your exampels above).