2033-C Depreciation

In 2003 we purchased a light leaseback property near Beziers. Occupancy was in June 2005 and so far we have no problems with the decision we made. We have made additions to the property which originally was a 1 bed mezzanine by adding a complete floor, which has provided a large upstairs bedroom. We now realise the mezzanine was a mistake for us.

Being a "light" leaseback the property is only let for 2 months of the year and we can have personal occupancy during the other 10 months of the year which means that my outgoings for taxes and maintenance will always be greater than my income. As I am still a UK resident, there is no way that I will ever be liable for tax - but the paperwork must be correct.

Since 2005 the tax + TVA has been handled by an outside accountancy company for which I pay 300€ p.a. At the present time I do my own UK & USA tax and see no reason why I should not be capable of handling the French tax system. I also have the papers supplied by the French accountants for the years since 2005 as worked examples. The actual TVA and tax papers give me no concern, but I am puzzled by form 2033-C

To this end, I have read "2033-NOT IMPÔT SUR LE REVENU (bénéfices industriels et commerciaux)" and also the section "calculez l'amortissement Robien ou Robien ZRR classique" which I found by a search on "Robien" and other related documents from the tax website (impots.gouv.fr ). However I have a few questions.

1) A web site that I found stated that the tax laws for Robien & Leaseback were different - but the site gave no details. Is this true?

2) On form 2033-C are the calculations for the depreciation on investments. My property is split in financial reporting terms into 3 sections. The first is the "Immobilisations incorporelles" which is depreciating at 33% and covers the legal fees. The second is "Autres immobilisations corporelles" which depreciates at 10 pa. The third section "Construction" however seems to depreciate at different rates per annum. On a base of 47594€ it has depreciated 2004=1421 2005=2380 2006=1428 2007=1428. 1428 is a rate of 3% which does not appear to tie up with the Robien documentation.

Can anybody explain the rates that apply for leaseback construction depreciation?
3) Perhaps this is the question that I should have asked first. Can anybody recommend a downloadable programme or spreadsheet to handle these tax situations.?