How to connect a beer engine to a polypin?

For those who don't know, a polypin is like a bigger, thicker 'wine in a box' bag that collapses as the beer is siphoned, leaving little room for oxygen / spoilage. I want to attach a beer engine to make it easier to use and get a better head using a sparkler.

1. Has any one got any idea / had any success in doing this? The setup would need to be airtight, as my beer lasts for months when just using the polypins built-in tap.

2. Can a beer engine pull still drinks? There is obviously a little co2 left in my brew but not enough to give ny kind of pushing force.

3. Does it matter where the polypin is in relation to the beer engine? What would be best.

4. The retailer of the beer engine says that you have to keep cleaning the tubes etc, but obviously I can't keep taking the tubes off, exposing the polypin contents. How long would it take for oxygen or off flavours to travel from the nozzle of the beer engine, along 3 meters of tubing and into the brew in my bag?

Beer engines were originally designed to draw beer from casks in a bar's cellar, so you shouldn't have any problem as long as the engine is with 3 meters and the tubing you use is thick-walled. There won't be no flow back from the engine to the keg.

Having never seen a polypin, making a recommendation would be rather difficult. The beer boxes I've used have a tap where you rotate the handle to dispense and the beer flows until you shut it. For something like that, it would be relatively easy to connect a line to the tap. If the polypin has a tap where you have to hold in a button to get flow, that would be much more difficult.

Kegless' site is rather unhelpful.

Symptoms - There is a sound of gas from the tap.
Diagnosis -

o If there is a sound of gas coming out of the tap it means that the keg is finished - either change to the next keg (if applicable) or order more next time!

Thanks! Very helpful! Good news, the polypin uses a tap, not a button!

I just bought my beer engine on ebay less than an hour ago:

http://cgi.ebay.co.uk/TRADITIONAL-H...286.c0.m14&_trkparms=66:4|65:13|39:1|240:1318
EDIT: link might only work if logged into ebay

How does it look? Is it all there?!
It cost about £50 with postage which is twice the price of the cheapest ones but I like the look of it, and they can be over £150 new.

So what's all the silver box in the last pic. Is that the "water jacket for cooling"? What are the two holes in the silver box for? One to connect hose and another for something else?

It's been a successful day I think. I suddenly remembered I spent big money on a powered coolbox that works off mains, LPG or battery that was only getting used when camping once a year. My 90% full 20L polypin fits PERFECTLY! I've had a thought that I could keep this chilled polypin down in the garage and pull the grog through the beer engine from the kitchen above! Is 15 feet up and 15 feet along doable please? I guess it can be pulled ok, but won't be chilled until the 3rd pint!