You can indeed use the attach command. Did you already try it?
http://www.sqlite.org/lang_attach.html

Now that I now a bit more about your program, why don't you display the data directly to the experimenter without going through the database first? Or did you already do that? At least, this should eliminate any lag from the database. The database can then be used as a "tape recorder".

Edit: ohh and sorry for the indirect questions to your question. I'm trying to understand what you want to do and why.