> is there a way in xslt to force the creation of xml files
> with apostrophed attributes instead of quotation marked values?

No.
>
> the reason why we need apostrophes is that a silly
> application we're using seems to accept only apostrophed
> values and quotation marks are causing troubles.

You could try writing your own serializer, or modifying (subclassing) the
serializer that comes with your XSLT processor.

Cheers,
Wendell