Modern "virtual PC" software relies on virtualization support features in the host CPU, and that the virtual machine has the same instruction set as the host. So programs are executed directly, with "traps" stopping execution when the host needs to do something behind the scenes to maintain the virtualization. This would not help you.
If you're on Linux, you could try running the program in Valgrind, that provides a 10X slowdown in most cases. :) It's not by design though, so it's not a long-term solution.
