How to highlight one character by number of column and number of line?

1

how to highlight one character by number of column and number of line ?

2

To go to line 10, character 12
10g11l
or you can do
10g12lh
if you are writing a command and don’t want to automate the minus one.

3

If you are writing a command, you could also do:

select 10.12,10.12