Purpose
=======

Can I select columns using `dplyr` conditional that the column name is in an external vector. I have found some posts that explain how to subset the data frame using a vector of name, but I could not find one when some of the names in the vector do not exist in the data frame.

Example dataset
===============

```
  library(tidyverse)
  library(tibble)
  library(data.table)

  col_names <- c('a', 'b', 'e')

  rename <- dplyr::rename
  select <- dplyr::select

  set.seed(10002)
  a <- sample(1:20, 1000, replace=T)

  set.seed(10003)
  b <- sample(letters, 1000, replace=T)

  set.seed(10004)
  c <- sample(letters, 1000, replace=T)

  data <-   
    data.frame(a, b, c) 
# I would like to choose a, b that are in col_names vector. 

```