gawk'ing at end of line

Lines in the file can end
...998~01234
...998~12345
...998~00123
...998~0 which is the line I'm looking for.

The normal use of the script looks for data
well back from the end of the line, so if the
gawk says gawk '/520~001155/'
hey, no problem. But 998~0 is a special
case and fully half of thousands of lines
end 998~0something and I need 998~0(end.of.line)
998~0backslash-n doesn't work.
Ctrl-J blows up.

Any ideas?

Tks