I'm going to make an assumption about your contact method in my response. I'm assuming the letter infront of the contact name represents a business or institution, and the names are of contacts at the particular business or institution.
With a BB you will have to have a seperate contact entry in your adress book for each name, you can't have a comany with multiple names in it. I have that issue with multiple contacts at the same comany and the work-around I came up with is to put the company name in the "title" section. Example lets say you have two ppl who work at the romper room, John doe and Jane Doe. In your address book in title you put Romper Room then the name and other info you need for that contact. Do the same for Jane Doe. When you go to your address book and enter ro, all of the romper room contacs will be listed in order you simply scroll to the name you need to contact and your on your way.
I believe tho this is going to mean basically sitting in front of the comp for few hours and re-doing you contact list in Outlook then syncing it with your BB. I hopw this helps.
I just want a honest weeks pay, for a honest days work - Steve Martin.