Add a number/numbers to a 'send' group (excluding 'merge' groups).
Arguments:
String groupName:
Name ID of the group to add the numbers to.
String numbersArray:
numbers The MSISDN (mobile number) you wish to add, if you want to add more then one use a comma delimited list.
Returns:
an integer with the total of added numbers to the selected group.
Specific error codes:
A number was not of a valid format.
error code 404 is reported if the group does not exist. See General error codes.