# If you'd like to omit non-matching lines from the result; add ';d' to the end of the expression.
sed -E 's/(\d+[A-Z]+)(\d+[-; ]+)(\d+\b)/$1$2$1$3/gi;t' <<< "987ABC11-15; 77; 877; 66-68
987ABC11-987ABC15; 77; 877; 66-68
987ABC11-987ABC15; 987ABC77; 877; 66-68
987ABC11-987ABC15; 987ABC77; 987ABC877; 66-68
987ABC11-987ABC15; 987ABC77; 987ABC877; 987ABC66-68
987ABC11-987ABC15; 987ABC77; 987ABC877; 987ABC66-987ABC68"
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