Al a couple of option to consider for achieving focus. The quickest and most non invasive is to remove the lens cell from a barlow and screw it into the 1.25" ToUcam adapter. You can find a bit more info here
http://www.astro-nut.com/sun-pst.html . Have a look at his site, there is some great solar info there. In particular download the Solar Primer PDF.
I'll let you know how I go with modifying an adapter (I have to get another one first incase I stuff up the one I have
)