<hr><i>rwilson added on 2009-09-22 18:55:18:</i><br>
double quoting doesn't work either, but i'm not sure its the shell.  technically you should be able to double-quote ("") or escape quotes with a carat (^").  windows powershell can escape with backquotes (`").  none of these methods appears to work with fossil.

<pre>
PS C:\fossil\xyntservice> fossil settings editor """c:\program files\jgsoft\editpadpro6\editpadpro.exe"" /newinstance"
Usage: C:\WINDOWS\system32\fossil.exe settings ?PROPERTY? ?VALUE?
</pre>