How to get base_baud frequency of a com-port in windows

Question

Is there a windows call to get the baud base frequency, like this one in linux.

struct serial_struct ser;
ioctl(com, TIOCGSERIAL, &ser);
base = ser.baud_base;

Answer 1

No, what I'm after is the internal clock used for generating baud rates. I want to calculate what non standard baud rates are possible to set. In linux it's:

struct serial_struct ser;
ioctl(com, TIOCGSERIAL, &ser);
base = ser.baud_base;
baudrate = ser.baud_base / ser.custom_divisor;