[R] Numeric Column Labels in Excel Function

[Dustin Fife]

Hi all,

I frequently get requests to do data analysis where the person
references an excel column. e.g., "I want to analyze [insert complex
variable name], located at column AAQ in Excel."  I've been doing is
gsub and inserting a part of the string for the complex variable name,
then going from there. But, I was trying to make function that returns
the following vector:

excelVector = A, B, C, D,...AA, AB, AC...ZA, ZB, ZC,...AAA, AAB, AAC, etc.

In other words, the argument would have one argument (n, or the number
of columns), then it would return a list like that shown above. Then,
all I would have to do is

column.of.interest = which(excelVector=="AAQ")

But I'm a bit stumped. The first part is easy:

LETTERS[1:26]

The next would probably use expand.grid, but all my potential
solutions are pretty clunky.

Any ideas?