A webservice enables you to add an answer to an existing topic.
Here are the parameters
user : Pseudo of a forum administrator
pwd : password of a forum administrator
idforum : ID of the forum where the message should be edited
idcat : ID of the category where the message should be edited
idtopic : ID of the topic which contains the message to be edited
text : text of the first message of the new topic
Here is a script example based on the Add Answer webservice, done in PHP
If everything goes right, the answer should be added to the topic and should return the two following parameters:
idanswer : returns the ID of the reply that has been added
status : Returns a message that confirms the reply addition