How to fire external flashes (G1)?

I would like to fire one of those Metz flashguns which has a camera bracket and a battery on a shoulder strap. How can I connect it to a G1? There is no external flash socket on the G1 and I can't use Canon's external flash adapter as the Metz flash does not have a "sole" to fit into a hot shoe.

I would like a little device with a flash socket connector to fit into the G1's hot shoe. I would then plug the Metz into the connector on the device. Is such a device available?

I know that the flash won't work with the camera's flash system and that I will have to use the camera in manual mode.
Roger

HI,
As extra flash, (rarely) I use my old CT45 and a vivitar SL-2 photocel.
Succes.
Miel

Since your Metz uses a current higher than 6.0 Volts
to sync with your camera, you'll need to use a hot shoe that can regluate that current.
The Wein Safe-Sync HS PC shoe adapter. $40-$50
Since the advent of digital cameras with hot shoes, my local camera shop sells them pretty quick.
An electric eye slave won't work reliably because the built in flash put out 2 bursts. One at low power to read the scene, the other to actually expose the film.

pieters1: Wow, I don't know how your system works, but you defy everything I read about G1 flash sync. I'll have to investigate the SL-2. Or does the G1 only output a single full power flash in manual mode?

I just checked, at manual mode the internal G1 flash gives only a single burst, at full power with no way to cut it back. (a good firmware update possibility!) So a electric eye type slave will work, but only if the G1 internal flash doesn't interfere with your lighting scheme, such as a studio type setting.
The hot shoe adapter will offer greater flexibilty.
I have an ol' CT45 myself...I will never part with it.