Does anyone know if there's a mechanism to pipe the build output window to a file?
I don't think this is exactly what you want but I'll throw it out anyway. I build from an external editor using a command line command that looks something like this.
c:\keil\uv3\uv3.exe -b -oc:\temp\foo.err c:\temp\foo.uv2
http://www.keil.com/support/docs/1830.htm