Hi vala !
S35/C35 Service Software can unlock the phones. First install it, than overwrite the default.ini and copy the map directory in the install order. In this there are some MAP's. As standard file select the Standard Map for your phone type. For the second one select the Map which has the name of your phone and of the provider u want to use in it. After that connect phone and start. And u can use your phone in the other provider.
U only can use it, if you have the map file without any Providerlock information or the Map for your provider. Clear ? If the right map file is not with your program wait ... !!
Because on
http://www.gsmfactory.com/ there is a version but the maps are only for a few provider included.
b.R.
GSM-Lupo