How to enable debugging in Express app when hosted in iisnode?

[Joshua Golub]

I would like to enable Express.js debugging as per these instructions. I tried adding this attribute to <iisnode> in my web.config file:

nodeProcessCommandLine="set DEBUG=express:* & %programfiles%\nodejs\node.exe"

but that produced this error:

The iisnode module is unable to start the node.exe process. Make sure the node.exe executable is available at the location specified in the system.webServer/iisnode/@nodeProcessCommandLine element of web.config. By default node.exe is expected in one of the directories listed in the PATH environment variable.

What is the best way to accomplish this?

Thanks in advance for your help.

-Josh