How to automatically export contacts from Thunderbird?

Google Contacts: How to force MS Excel to import a CSV file without messing up with leading numbers like '0' or '+' sign automatically?

• I've more than 11,000 contacts in my Gmail address book and they've been aggregating since 1990's in different formats from Netscape Navigator to Netscape Communicator to Mozilla Thunderbird and finally Gmail. These email contacts also converged with phone contacts coming in from mobiles from Nokia 8310 to E61 to E71 to Android. In short, they are all juxtaposed combining different address book formats over 2 decades. Some phone numbers are listed in 'Home' column, some in 'Work', etc. and some start without international dialing codes e.g. 0300-XXXXX (notice leading number 0) and some with international e.g. +92-300-XXXXX (notice leading + sign). The challenge is if I export the complete address book from Gmail in CSV format and try to edit it in MS Excel, it removes the leading '0' if the phone number is saved without international dialing code. It also removes the '+' sign if the number is saved with international dialing code. How to force MS Excel to import a CSV file without messing up with leading numbers like 0 or + sign automatically?

• Answer:

  Don't double click the CSV export. Rename it to <filename>.txt and use the Excel import function. That will allow you do designate the comma as the delimiter and tell it to treat specific columns as text instead of numeric. Data Tab / From Text (under external data) - Point to the txt file and click import and follow the prompts from the wizard.