you should be able to get how to do it from my AU paper last year.
I will admit that the last attempt I made was before sp3 for 2007, but I seem to remember problems getting the data to match our Excel chart which is now treated by reviewers, contractors and other engineers as the final and definitive word for all things storm sewer with our plan and profile sheets being reduced to merely an instruction manual.
TheChart has grown to a huge behemoth complete with embedded macros that must be painstakingly recreated one pipe run at a time for each project and no two charts are ever identical. Each run of pipe has 4 unique cells it must refer to to be sufficiently labeled for pipe full velocity, pipe full 10 (or 100) year design velocity, pipe full flow and pipe 10 (or 100) design flow. We still can not get the pipe full velocity numbers derived from the chart and rely on a second program to generate this value which we have to enter directly. Once it is determined that all criteria is met, the whole thing is pasted into a titleblock and into the construction documents where it rules supreme.
I will try again to get the required values to generate through a label expression if you can at least assure me it is possible generate labels that will exactly match. All this also keeping in mind that my pipe networks are still extremely fragile with pipes spontaneously snapping to the centers of the structures rather than the inside wall faces I am designing to with no warning and worse, no fanfare which leaves many "surprise" gifts for me when I next zoom in on my pipe network.