Investment account export then import

[Elwood]

I see there is transaction export and import both in CSV format. However, it looks like the format is not the same (at least when doing transaction from an investment account). I noticed there are several conversion utilities (QIF, OXF, CSV) available for download from various places online, but it's hard to tell which of the free ones will actually help with trying to import Gnucash formatted investment transactions back in.

What I'm really trying to accomplish is duplicate a series of investment transactions from one college savings account to two others.  In one case, the real world transactions are identical for two accounts and at least similar for the third. (For the US audience, think 529 plans for three kids, one with a later HS graduation date. )

Anything I should be looking at or doing differently?