How to extract columns from a row and save the output as a variable dplyr

A reproducible example, called a reprex would be helpful to troubleshoot the issue.

When you say

a specific column from a specific row

do you mean a single value? If that's all you're trying to do ...

mtcars[3,2]
#> [1] 4

Created on 2019-11-25 by the reprex package (v0.3.0)

gets you the second column from the third row.