Referring the base of a branch

[Derrick Bass]

I did something dumb and created a branch without tagging the base of  
the branch first. Now I want to merge the changes on the branch into  
the mainline, but I can't figure out a way to refer to the base of  
the branch in a cvs update statement. (Using -j Branch-name gets me  
the tip, of course.)

Is there a way to that? If not, what's the best way to merge the  
changes?

Thanks in advance.

Derrick