Pierre, when I googled to see if anyone may have an answer, I see that the first result (searching for coldfusion builder snippets homesite) was in fact an Adobe forum thread from last year where you asked this same question.
There, Rob Brooks-Bilson offered a solution that you said you'd take a look at. How did that go? I realize it may be that you lost track of it and are facing the challenge again.
While he shows doing it from HS+ to CFEclipse, note that CFB and CFEclipse are both Eclipse-based IDEs, so what applies to one often applies to another.
(That said, the second link is to a discussion of more specifically moving snippets from CFE to CFB: http://forums.adobe.com/message/2111627)
I don't see too many other people offering a solution, but let's start by seeing if the above works for you.
Providing fast, remote, on-demand troubleshooting services for CF (and CFBuilder)