Login to your e-smith box as root.
pico /sbin/WirelessRestart
[Add these lines]
#!/bin/bash
/sbin/service ppoe restart (Isn't it ppoe, not pppoe?)
[Save Changes]
adduser -r wireless -c "Wireless Restart Account" -s /sbin/WirelessRestart
passwd wireless
[Set a password]
Then, using plink you could create a batch file that would:
plink -l wireless -pw [password] aaa.bbb.ccc.ddd /bin/false
Where, aaa.bbb.ccc.ddd is the IP Addr of your E-Smith box.
Hope this helped,
Nathan