How to get code page of font by using font file name in c++

Question

I have the font file name. I have to set code page at runtime to get HPDF_Font handle in LibHaru PDF lib. Currently, it is using CP1252 code page. We need support fonts from other code pages.

Code snippet:

const char * font_name = HPDF_LoadTTFontFromFile(m_hPdfDoc, ttfFile(), HPDF_TRUE);
HPDF_Font hFont = HPDF_GetFont(m_hPdfDoc, font_name, codePage); //

Is there any way to get code page by using font file name? Or is there any other way to get the code page at runtime?