>Does anyone know if there is a Windows API behind the LastKey() function of VFP9 which can be called directly?

I don't think there would be, since Fox doesn't use system events for managing its Read statement, not in this sense. LastKey() returns the code of the key used to terminate the Read statement, and it's a function which existed since Fox for DOS, i.e. it was written before Windows were an option for Fox (and when it had Unix and Mac versions).