assume you you have some text like this:
<-------unknown area
<-------blank lines
.....0.....<-------dot represent unknown character
.....1.....
.....*.....<-------unknown number of lines, the 6th column is not blank
.....3.....
.....4.....
.....5.....<-------your cursor at 5
.....6.....
.....7.....
.....*.....<-------unknown number of lines, the 6th column is not blank
.....9.....
.....0.....
<--------blank lines
<-------unknown area
what's the simplest way to select from 5 to the first or last 0 in visual block wise mode? Please don't use character value(such as /0 or ?0), don't assume there are 11 lines(such as 5j or 5k), don't assume there are 11 columns.