Thanks Stan. I have downloaded and run the code from the link you shared ("Just launched new open source project QrCode.Net at http://qrcodenet.codeplex.com").

The QR codes seem to work, however, non-regular characters are not understood properly (like Ñ, Å, Æ). The standard 128 ASCII chars work fine, so it could work with URLs.

I guess this code could be used as a DLL in Reporting Services and then solve the problem (to some point...)

Thanks again,

Antonio.