Changing font on custom pages header

I'm using MUI_HEADER_TEXT to set a header on a custom page. I can get a pointer to the controls that are included from my ini file, but I'm struggling to do the same with the header text. I used Resource Hacker and it looks like the id is 1037. So, I've tried the following:

Function DoPrefacePage

	!insertmacro MUI_HEADER_TEXT "text" "subtext"

	!insertmacro MUI_INSTALLOPTIONS_INITDIALOG "preface.ini"

	Pop $HWND

	

	GetDlgItem $DLGITEM $HWND 1200

	CreateFont $FONT "Tahoma" 12 900

	SendMessage $DLGITEM ${WM_SETFONT} $FONT 0



	GetDlgItem $DLGITEM $HWND 1037

	SetCtlColors $DLGITEM 0xFF0000 0x00FF00

	SendMessage $DLGITEM ${WM_SETFONT} $FONT 0



        !insertmacro MUI_INSTALLOPTIONS_SHOW

FunctionEnd

This works for the first control (a label), but fails for the header text. Do I have the wrong id? Is the header text different from the other controls?

Any help is appreciated.

Use
GetDlgItem $DLGITEM $HWNDPARENT 1037