time confusing of upper tribunal

hi, my first tribunal appeal has been dismissed. i have been told by this forum that, i have 28 days to make a fresh application. now my confusion is -

if i apply to go for upper tribunal and if they refused to accept my appeal as a upper tribunal appeal, in this case how will this 28 days will count to make a fresh application. will it be tha date of refusal letter of first tier tribunal or the appeal not acceptance letter of upper tribunal. may be i made it complicated
for example-
appeal dismissed of first tier tribunal ---------------------10 dec 13
applied for upper tribunal .......12 dec 13
upper tribunal did not accept the appeal in their court ..18 dec 13

in this case, if i want to make a fresh application from which date my 28 days will be count, as my visa has been expired.
thanks