I'd love to have this feature as well, but have yet to find anything like this. Let me know if you do.
Otherwise, you may have to suggest it to Quaxi, if it hasn't already been suggested.
It's a pain when trying to edit BHAVs and you want to replace all the instances of something in a similar fashion. It'd be great if we could do a global replace rather than having to hunt and peck each line of code. But I wouldn't know if this would even be feasible.
Ste