I installed an quantlib on my mac, but have no idea, how to start using it with an excel. Please advise hoq to do it. I followed all instructions here: http://quantlib.org/install/macosx.shtml. I think I need a kind of add-in or so.
The QuantLib you installed is just a C++ library.
If you were on a Windows machine, you'd need the QuantLibXL addin to use it in Excel (http://quantlib.org/quantlibxl/). But on a Mac, you've no such luck. As far as I know, Excel for Mac only allows addins written in VBA, so QuantLibXL can't be built for it.