Fair enough, but that is using the "bigger script" optimal? So far you haven't told us that there's any substantive objection to having the "bigger script" shell out... or pre-selecting a worksheet (worksheets?) to convert before it (they?) provide data in cvs format to the "bigger script.
One reason the latter might be sub-optimal would be that the "bigger script" is -- in effect -- merely a kind of batch file -- one starting a series of (non-native executables?) actions on a large set of spreadsheets... but even that seems amenable to re-factoring, if Tux' reply (above) doesn't meet your needs.
