AviAddXSubs can convert ANSI .srt files to idx/sub or embed them in .divx video as XSubs.AVIAddXSubs
Update has context menu support in Windows 64 bit. Right click an .srt or supported video file to use with that file.
Unfortunately it doesn't support UTF-8 or Unicode. Only ANSI .srt. Many times you can load a UTF-8 or Unicode in Notepad and save as ANSI to get it to work.
I've been using this app for years. Nice tool.