How to sort on column for rows containing a certain word

Question

I want to sort on a certain column only for rows containing a certain word. I don\'t want to see rows not containing that word. For example I have this text file:

Answer 1

Pipe your input to an external command:

:%!grep sdf | sort -n -k3

Details:

1. select the whole content using '%'
2. pipe it to an external command using '!'
3. grep onyl the lines containing 'sdf'
4. sort these lines numerically (-n) on the third field (-k3)