RFE: taskopen -x <executable > < id | filter > [ \\label ]
-x as in executable

The -x flag overrides the executable that is used to open an annotation. 

Sometimes, you might want to open .html using your $EDITOR, and conversely, it's possible to open a .txt file with your $BROWSER, and sometimes, you want to use applications we'd never think of. 

As an example, with this option, it might be possible to do things like
taskopen -x wc < id | filter > [ \\label ]
which would (after selecting from multiple matches) do a word count of the selected annotation. 

If the application used arguments, they would probably need to be quoted, as in
taskopen -x 'wc -l' +bugs \\notes
