My idea is to make 4 stained glass windows to clad a square cake. I want to make the leaded window from sugar paste and fill the 'panes' with coloured sugar syrup. Has anyone tried this technique or is there another method to achieve a transluscent effect?

I can't get the photo to load, but if you click on my gallery you'll see a stained glass cake, for which I used tinted piping gel. The white base for the glass pane and the lead portions are fondant.

Perhaps the hot sugar syrup might melt the fondant?

if you're interested, Kimberly Chapman has developed a tutorial for making stained glass out of gelatin:

http://www.eat-the-evidence.com/2012/05/16/flexible-edible-stained-glass-ebook-now-available/

If you want to use hot sugar candy then make a royal icing frame and dry it completely. Or a cookie frame (I suspect you are thinking of the stained glass cookies that have candy that melts in the oven).

Pouring candy precisely takes LOTS and LOTS of practise as well as a design with few corners. Pipe the outlines with royal icing onto sheets of gelatin, and use piping gel which does slowly crust, and you will neither burn yourself nor waste your time. These windows will stand up or can be glued into standing buildings if necessary.

If you want to use candy, then make sheets of that for your base instead of gelatin. But you MUST keep the pieces in a dessicator to make sure they don't start leaking when they absorb humidity.

We used to use lifesavors. Melted them in a design in the oven and let them cool. If its an abstract shape you can do this, break up the pieces and put them together with royal icing. Pretty and yummy too !

Thanks everyone for the posts, i will give it a go one way or another (not sure if some of the products are available in the UK or maybe its just unfamliar terminology(lifesavors?)) At least i know it is possible. Fingers crossed

I use crushed sour balls in silicone molds.

I use crushed sour balls in silicone molds. That's how I did these butterflies: http://cakecentral.com/gallery/995093/basket-of-pink-roses-cake

"Lifesavers" in the US are a type of hard candy that is in the shape of a ships lifesavor ring. Any type of hard candy crushed and melted may also work - Good luck !