Roku support for arabic text

Can we use the arabic true type font with respect to roVideoScreen? our main problem is with respect to subtitles in the video as majority of our users are arabic origin we want to provide them with the arabic subtitles.

As far as i know here is the working example for english subtitles, if i give arabic subtitle .srt file the system doesn't understand the format and display square boxe for each char. can you please guide me with a snippet to achieve the arabic subtitles with respect to .srt file.

video = CreateObject("roVideoScreen")

videoclip = CreateObject("roAssociativeArray")
videoclip.StreamBitrates = bitrates
videoclip.StreamUrls = urls
videoclip.StreamQualities = qualities
videoclip.StreamFormat = streamformat
videoclip.Title = title
print "srt = ";srt
if srt <> invalid and srt <> "" then
videoclip.SubtitleUrl = srt
end if
video.SetContent(videoclip)
video.show()

Thanks,
Ramakanth.G