The same issue pops up every once in a while with Romanian because some fonts simply lack foreign characters (ă, ș, ț, etc), so most of the time I have to copy-paste the regular letters and add commas (,) and various other symbols to them.
TypeTool 3 is what I would recommend for editing fonts. It does the job very well. For something more complex there's FontStudio, but it's more for professionals really. If you're looking for something free, there's FontForge. Except it's for Linux. So if you're using Windows, don't bother with Cygwin. Install VirtualBox and grab a LiveCD copy (700 MB) of Ubuntu, or look at least look
here. FontForge may not look pretty but it's written well and does a good job.