Use -b on the isql side and use "print" statement inside the procedure to output custom header lines where you need them.
To speed up your work you can first capture the header(s) you need with a normal isql run first.
print "<your captured header>"
print statement also has parameter substitution format where you can put heading and variable values side by side.
e.g. with two variables @myname and @mystate
print "My name is %1! and I live in %2! state ", @myname, @mystate
will print something like this assuming proper values in the two variables.
My name is Avinash and I live in Indiana state.
HTH
Avinash