WOL Connection To USB-UIRT

I would like to pull a signal voltage from the USB-UIRT to trigger an external circuit so I can power on my HTPC from totally off.
I have read threads on other forums in regards to supplying a signal voltage to the WOL or WOR motherboard connector, but none addressed where to get this signal from on the USB-UIRT.
Ultimately I would like to interface this output voltage with an external circuit utilizing a optocoupler connected in parallel with my power switch. This would allow power on/off without requiring a motherboard with a WOL or WOR header.
Does anyone have any suggestions or advice on how to achieve this?
I have read threads on other forums in regards to supplying a signal voltage to the WOL or WOR motherboard connector, but none addressed where to get this signal from on the USB-UIRT.
Ultimately I would like to interface this output voltage with an external circuit utilizing a optocoupler connected in parallel with my power switch. This would allow power on/off without requiring a motherboard with a WOL or WOR header.
Does anyone have any suggestions or advice on how to achieve this?