ExcelBanter - How do I search a worksheet for a custom "text" max and min value

I've got a worksheet that is used as a practice log for musicians. There is a
column for "Dynamic Range" where they can choose from a drop-down list the
lowest (in one cell) and highest (in the next cell to the right) dynamic
(i.e. musical volume) for that excercise. The dynamics a

pppp
ppp
pp
p
mp
mf
f
ff
fff
ffff

These are musical terms that are listed from quietest (pppp) to loudest
(ffff.)

How can I make a formula to look through the worksheet for the day (which
might contain several different excercises with different dynamic ranges
chosen) and pick out the quietest dynamic and the loudest dynamic to form a
total dynamic range for the day?

For example,

If one excercise has the dynamic range of pp-f chosen, and a second
excercise has p-f chosen, and a third excercise has mf-ff chosen, the formula
would return a total dynamic range of pp-ff.

Is this possible?