library(dplyr)
## My list of names
name_list = list(c("A", "B"), c("C", "D"))

## Some random function to perform calculations
random_function = function(input){
    input/10
}

## The reason you see name_list[[1]][1] is because I wish to do this repeatedly for different list of names.
data.frame("A"=c(1,1,2,2,3,4), "B"=c(1,3,5,7,9,11)) %>%
    mutate(A2 =  random_function(name_list[[1]])[1])

data.frame("A"=c(1,1,2,2,3,4), "B"=c(1,3,5,7,9,11)) %>%
    mutate(A2 =  random_function(A))