Hi there,
I may be able to help a little on this. I am an access student however came from Perth's "Pathway to Medicine" program rather than Stow's access program. UKCAT was not needed to get into the access program however it was a requirement OF the course as if successful in the access program, we were to be presented to St Andrew's for a second interview. If successful, we would gain entrance to the Uni but of course the UKCAT would have had to be done therefor they made sure it was done before the cut-off date. I would just call Stow to ask if you actually need it for entrance. I have heard of some access programs asking for it as a pre-req and have offered conditional acceptances based on a UKCAT score. Again, impossible to say without speaking to the college and asking exactly what it is they need you to do.
Just for the record, I would not only speak to the college about the access program but also Glasgow Uni's medical admissions dept to ensure eligibility and also to find out exactly what they look for in access student.
I am starting 1st year at Glasgow this year as an access student and if there is anything I can assist with, please ask away! Prefer PM though.
-Bubz