In writing some Vimscript to try to answer this question, I was exploring ways to "search for a line with pattern P in position X" (P is a search pattern, X is a number).
One way to do this would be to search for (e.g.) ^.....[a-z], where [a-z] is the pattern, and 5 is the position.
But how would I use Vimscript to make ....., from . and 5?
Simply use regex syntax for "repeat n times":
/^.\{5}[a-z]
This searches for 5 .s and then an [a-z].
If you just want to repeat a character c n times, simply do:
let dots = repeat('.', 5)
" dots is now '.....'
Vim also has this nice feature /\%5c[a-z] which matches [a-z] only in column 5. You can read about it in more detail in :h \%c. There is also \%v which is to be used for virtual column which is relevant in case of a lot of wrapped lines and it will match the virtual column even for the wrapped lines.
