My C++ windows program uses htmlhelp. Structure HH_POPUP includes field pszFont in format: "Facename[, point size[, CHARSET[, color[, PLAIN BOLD ITALIC UNDERLINE]]]]", but I cannot find any info about way to define the charset. My russian popup help is totally unreadeable.

HH_POPUP popupAttr;
memset(&popupAttr, 0, sizeof(popupAttr));
popupAttr.cbStruct = sizeof(popupAttr);
popupAttr.clrBackground    = COLORREF(-1);
popupAttr.clrForeground    = COLORREF(-1);
popupAttr.rcMargins.left   = -1;
popupAttr.rcMargins.bottom = -1;
popupAttr.rcMargins.right  = -1;
popupAttr.idString = UINT(helpInfo->dwContextId);
popupAttr.pt       = helpInfo->MousePos;
popupAttr.pszFont = _T("Arial,18,HOW_TO_DEFINE_THIS_CHARSET"); // please!!!
CWnd::GetDesktopWindow()->HtmlHelp(reinterpret_cast<DWORD>(&popupAttr), HH_DISPLAY_TEXT_POPUP);