Changing treatment labels when using blockrand() function

I am using the function blockrand() to generate block randomizations. I have 24 subjects, 2 treatments, and want to make blocks of 8. The code I am using thus far is blockrand(24, num.levels=2,block.sizes = c(4,4), uneq.beg = FALSE, uneq.mid = FALSE). The treatments come out as A or B. Is there a way to change the labels A or B to E or C for experimental or control?