I could have sworn that I had created one previously via the Outlook
user interface. Only in 2003, I couldn't for the &(*@&## life of me
figure it out, then when I was working on something completly unrelated,
I realized that I had already created the user field already way back
when (six+ months ago). I don't use Outlook from a developer standpoint,
so things get rough at times.
I haven't pursued it further since I discovered that I had in fact
created the field that I needed at the folder level nine months ago back
when I was using Outlook 2002.