An application sends the IMC_GETCOMPOSITIONFONT message to an IME window to retrieve the logical font used for displaying intermediate characters in the composition window.
msg = (UINT) WM_IME_CONTROL;
wParam = (WPARAM) IMC_GETCOMPOSITIONFONT;
lParam = (LPARAM) &LogFont;
 Returns zero if successful, nonzero otherwise.
  Windows NT: Requires version 4.0 or later.
  Windows: Requires Windows 95 or later.
  Windows CE: Unsupported.
  Header: Declared in imm.h.
Input Method Editor Overview, Input Method Editor Messages, LOGFONT