I'm curious if it's possible to specify an envrionment variable in the `ProgramArguments` portion of a luanchd script on Mac OS X Leopard.

```
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
    <key>Label</key>
    <string>me.mpietz.MountDevRoot</string>
    <key>ProgramArguments</key>
    <array>
        <string>/bin/sh</string>

        <string>$HOME/bin/attach-devroot.sh</string>

        <!-- Instead of using...
        <string>/Users/mpietz/bin/attach-devroot.sh</string -->
    </array>
    <key>RunAtLoad</key>
    <true/>
</dict>
</plist>

```