Seeking of tutorial / technology to create a web UI tool that will create an Excel workbook

I'm a beginner that has a dream (and some experience) to put his multi user Excel macro into a web platform. So I wouldn't have to send distribution emails with every single update. The input to the macro consist of excel files or can be substituted with a database. My answer is what technology and what tools should I use? Best solution would be open source technologies with portable GUIs. I'm looking for solutions with tutorials, I'm not so experienced as i would wish. Please toss me some links. Regards Michal