There is currently no one-stop solution that provides reading and writing of Excel files without Win32::OLE. Putting one together with both WriteExcel and ParseExcel shouldn't be too hard. If you want some help, I'd be glad to give some advice. A solution using tie and DBM::Deep for the data structures might be kinda cool.
My criteria for good software:
Does it work?
Can someone else come in, make a change, and be reasonably certain no bugs were introduced?