OK, here goes. the basics of a glaze are (as I'm sure you're aware) an alumina, a silica and a flux. the glass has the silica so it can replace the quartz or flint or whichever you choose to use. What I do is insert glass frit in a dry state, and mix a wet batch of base and apply. Using colourant (in my case Cobalt DiO2) and firing slowly to the glass temp. Most stained glasses have a slumping temp of around 800 degrees and a melting temp of 847-900. The clay I use for this is pre-biscuit fired Terra-Cotta as it is a relatively low fired clay. The annealing temp should be brought down very slowly to allow the glass to fuse to the ceramic vessel. There is a book on glass slumping featuring glass slumping and ceramic mixed media that may prove useful written by Joy Bosworth that can be bought very cheaply online. Hope this helps.
Although I am new to ceramics, I love the idea of fusing the two together. I have experimented with various types of clay and glass. the one I find that works the best (at least for me) is bullseye glass (finely powdered and and added dry). I'm still working on getting the annealing times right but hopefully it'll only be a matter of time. This example is of some terra-cotta clay with an 'off the recipe' glaze, bullseye frits, a teaspoon of china clay and a sprinkling of Cobalt DiO2. Like I said, still a work in progress.