Question Mysql question - Offset a value?

[Coume]

Hello,

** I posted this on vbulletin.com but now that I found out about this modification site, I guess here is the right place to post...

I just purchased a vbulletin licence to convert my phpbb forums to a vbulletin one.

Currently, I run 2 boards an English http://www.mythtvtalk.com/forum/ and a German http://de.mythtvtalk.com/forum/ one that share the same user databases, etc. I was pretty happy with this tweak at the time but now, it proves to be very difficult to merge them to create a single vbulletin one...

Anyway, I have a phpbb table with the following columns:

topic_id
forum_id
topic_title
topic_poster
topic_time
topic_views
topic_replies
topic_status
topic_vote
topic_type
topic_first_post_id
topic_last_post_id
topic_moved_id

Is there a way to offset the value of the topic_id field by i.e.: 386 in all records?
Therefore if a record has a topic_id = 34 after the SQL trick it should be replaced by 420.

topic_id = 34 -> 420
topic_id = 35 -> 421
...
topic_id = 5789 -> 6175
etc

Any idea on how to do that in MySQL?

Thanks
Ludo