Has anyone had any success getting a font to work with SendSysMessageCL??

I guess it means Unicode fonts which are different from the ascii fonts. The v5 client has a file for each of the 6 unicode fonts and the client uses these and they are different. I expected SendSysMessageCL to be able to use any of these 6 fonts.

But, I can't get the font to change at all. For example:
SendSysmessageCL(character, 500000, {}, font);
Where font could be from 1 to 6.
No matter what integer I put there is always displays the same font.

So.... does that mean I am the only one who has ever tried to set a font in SendSysMessageCL ??
Or is it that nobody has troubles with it except me?