I have exported a list of contacts from my mobile phone's contact
database into a CSV file. These contact records contain phone numbers
that have a plus sign in them noting international dialing codes.
(i.e. +44 7712345678 would be a british mobile phone number).

The problem is that when this file is opened in excel, the number is
automatically represented in exponential notation and the plus sign is
stripped.

How can I avoid this so that the number maintains it's plus sign?

Example: The phone number +44 7123456789 gets converted autmatically
to 4.47123E+11. Converting to text keeps the same formatting and the +
sign is lost.

Any suggestions?