In comdlg's page setup dialog, there is a little ss_whiterect static that shows a mockup page preview. MSDN says that the text shown on this page is some dummy greek text, and the WM_PSD_GREEKTEXTRECT message is one of the messages used in customization.
How can I find out what this "Greek text" dummy text is? I looked in comdlg32.dll for string resources and don't find anything there, and also cant find it in my en_US\comdlg32.dll.mui
Page Setup Dialog Box - Customizing the Sample Page
https://msdn.microsoft.com/en-us/library/windows/desktop/ms646962(v=vs.85).aspx#_win32_Customizing_the_Sample_Page
The Page Setup dialog box includes an image of a sample page that shows how the user's selections affect the appearance of the printed output. The image consists of a rectangle that represents the selected paper or envelope type, with a dotted-line rectangle representing the current margins, and partial (Greek text) characters to show how text looks on the printed page.
Why is this information so important? AFAIK it is encoded in Windows itself. You'd need to reverse engineer the DLL(s) that contain the functionality of the Page Setup Dialog or somehow obtain the source code.