Imagine I've got the following in a text file opened under Emacs:

some    34
word    30
another 38
thing   59
to      39
say     10
here    47

and I want to turn into this, adding 1 to every number made of 2 digits:

some    35
word    31
another 39
thing   60
to      40
say     11
here    48

(this is a short example, my actual need is on a much bigger list, not my call)

How can I do this from Emacs?

I don't mind calling some external Perl/sed/whatever magic as long as the call is made directly from Emacs and operates only on the marked region I want.

How would you automate this from Emacs?

I think the answer I'm thinking of consist in calling shell-command-on-region and replace the region by the output... But I'm not sure as to how to concretely do this.