generate new custom font (from Arial)

I have a software that generates PDF files. If I generate without font embedding the filesize of the PDF is about 25KB, but then Gmail pdf preview doesn't render some of the fonts correctly (Cyrillic letters). If I embed the Arial font in the PDF it becomes 950KB (almost 40 times bigger). I see the [login to view URL] file is 900KB and it includes many chars that I don't need in my PDF. I need help creating a custom font which will be a copy of the arail but it won't include many chars. I only need Cyrillic, Latin, Greek, interpunction signs, and numbers. So, I need to exclude Chinese, Hebrew, and other letters. Maybe put empty vector elements in place of the existing signs. The font should be generated under a different name. Hopefully, this will dramatically reduce the size of the generated PDF.