[GNC] find and replace

[gnu Gord]

Is it possible to find a specific split transaction based on the memo field
and assign the account to transfer for that split item?

Let me explain. I'm new to GnuCash and have just imported my Quicken data
QIF file but it appears that some transactions within splits have no
transfer account assigned. It appears that I did not have a category
assigned to them in Quicken. However, most seem to have the same memo text.
There are really too many to do manually so some sort of find/replace would
be helpful. If it's not possible within GnuCash, can the XML file be edited
directly?