um, is this instead of ure work experience or as well as?
cos if it's as well as, then it's all good, if u keep at ure job for a while, you show that u're determined, reliable etc etc
its good generally on ure cv.
however, personally i think working with sick/people in need would be better if you had the choice. have you tried residential homes, schools for special needs children, soup kitchens, does ure hospital need volunteers for anything? bank nursing, maybe even helping at after school homework clubs?
i think the chartiy shop is a good idea, but i don't think u'll have any contact with ppl in need, to show ure caring etc.
keep tryin with the work experience. can't you find out dr's names in the hospital/gps and write to them directly? that's what i did, my school didn't organise too much for us.
good luck
xxxx