Try:
# Data (I assume that each value is separated by 1 comma and some other punctuation)
x <- c("['032']","['A10', 'A11', 'B31']")
# Find maximum number of values in 1 string (counts the commas in each string and returns the maximum number + 1, as that is the most values there are)
mx <- max(sapply(gregexpr("\\,",x),length)) + 1
# Create a matrix containing each value in a separate column; str_split_fixed can take an argument that will determine the number of columns (mx in our case)
library(stringr)
str_split_fixed(gsub("[^[:alnum:],]","",x),",",mx)
# [,1] [,2] [,3]
# [1,] "032" "" ""
# [2,] "A10" "A11" "B31"
If each string only has one value, then you'll get a matrix with two columns, of which the second column will only have empty strings. Otherwise, it should work just fine.