Dear all,
I’m having some issue in creating a report for the authority for witholding tax on suppliers invoices.
The witholding tax in Italy is due on cash basis even if our accounting is on accrual basis. So my reporting should state a list of all the details of the invoices (supplier, invoice nr, amounts, VAT and so on) that are subject to witholding tax that were paid in a certain period.
I imagine that is going to be best done with a localisation report, so a final solution will need to wait till lubos has updated the localisation framework and withholding tax approach.
Which I guess you already knew, but wanted to ensure the changes lubos is implementing above will be compatible with Italy’s requirements 
You might experiment with a spreadsheet created from contents of the clipboard obtained during a Batch Update (without going through with any update). That could be the easiest way to get all the information you need at one time. I suspect you are going to need to manipulate data in spreadsheet at some point in the process anyway. You might as well start there.
Having said that, I also must say that, since I don’t know what your report needs to include, I cannot say with certainty the approach would work.
You could probably help lubos and Italian users by finding an Italian government reference describing the exact minimum actual government requirements and if possible the stationary to be filled out if done manually.
I’m already doing. We are now working on IVA, ie VAT.