A little bit more complicate than Werner's solution, but with the possibility of storing whole 'counter' trees.
Use the package
xassoccnt, define a
backup counter group, say
pagebackup, populate it with the
page counter, store the state into some id (say,
roman) and restore it later on, after changing the counter output to
roman again with
In the example of usage below, the first five pages are numbered with roman figures and the appendix numbering continues with
vi, as requested.
I agree, that this is 'too' much for such one occasion, but good to know for other issues.