Accessing specific characters from a font

[kleinbottle4]

Hello all,

In groff/font/devdvi/SB there is the following line (74)

        BbbA    757307,722352   2       0101

for the blackboard letter A.

How can I actually input a blackboard letter into a groff (-Tdvi)
document? Is there a command like ``\[u....]''?

Thanks,
kleinbottle4