The most flexible way to achieve this is by using a mapping table. If() statements are fine as long as the code never needs to change, but what if you decide in the future that 'CC' should change to 'Web' as well?
Let's assume you have an Excel spreadsheet that contains the values in field A that should be changed and what they should change to. E.g.:
In your QV script, load this as a mapping tbale:
MAPPING LOAD FieldA,
Then, when loading your data, refer to this mapping table using ApplyMap() with FieldB as the third parameter so that for all FieldA values not in the mapping table, the original value of FieldB will be returned: