Troubleshooting Import Filter for JSTOR

I’m trying to update the JSTOR import filter for my campus now that their content and apparently their data structure has changed, and I’ve run into a problem that I don’t know how to solve.

JSTOR currently separates out the title and subtitle of a work, so, for example, the RIS export uses TI as the tag for the title of a book chapter, T1 as the subtitle for the book chapter, T2 as the title for the book, and T3 as the subtitle for the book. I can of course get all of these bits into an EndNote record, but they come out with the titles and subtitles separated by line breaks. Is there a way to have EN concatenate the data so that they get separated by a semicolon instead?

So, for example:

TI  - SPRING

T1  - PLANT

T2  - The Land of Milk and Uncle Honey
T3  - Memories from the Farm of My Youth

When this gets imported the chapter title field then looks like:

SPRING

PLANT

And the book title field looks like:

The Land of Milk and Uncle Honey

Memories from the Farm of My Youth

And I would of course prefer:

Spring: Plant

The Land of Milk and Uncle Honey: Memories from the Farm of My Youth

Thanks for any advice!

~ Iris