# If you'd like to omit non-matching lines from the result; add ';d' to the end of the expression.
sed -E 's/(?:\)[;,]( )|([A-Z\d]+))|./$2$1/gm;t' <<< "4A(4,5,6,7,8,9); 4B(4,5,7,8); 3A(1,2,3); 3B(1,2,3), 3C(1,2)
4A (4,5,6,7,8,9); 4B(4,5,7,8); 3A(1,2,3); 3B(1,2,3), 3C(1,2)
4A (4,5, skip 8,9); 4B(4,5,7,8); 3A(1,2,3); 3B(1,2,3), 3C(1,2)
4 A(4,5,6); 4B(4,5,7,8); 3A(1,2,3); 3B(1,2,3), 3C(1,2)"
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