# If you'd like to omit non-matching lines from the result; add ';d' to the end of the expression.
sed -E 's/.*\s-s?n\s*(.+?)(?:\s-.*|$)/$1/;t' <<< "msqlsum81pv 0 0 25 25 25 2 -sn D:\\workdir\\PV 81\\config\\sum81pv.pwf -C 5000"
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for SED, please visit: https://www.gnu.org/software/sed/manual/html_node/The-_0022s_0022-Command.html