I am having the same problem. I use BW 8 with the Israeli keyboard and I am unable to get the @ for a Hebrew search, I only get פ or ף. It's maddening. I have just spent the last hour trying to get this to work. BW is powerful but sometimes it's incredibly user unfriendly. Any help would be appreciated.
Once you've typed your verb, you have to go back manually to the beginning of the word (i.e., to the right, just before הלך), then type in your @. That should do the trick.