These look like fixed-width records to me. That's a job for unpack.

Something like this would tell lines that start a new record apart from those which don't:

while(<>) {
    chomp;
    my ( $cnum, $details ) = unpack "x a5 x a*", $_;
    if( $cnum =~ /\d/ ) {
        # new record
    }
    else {
        # follow-up line
    }
}
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The string left in $details for follow-up lines seem to roughly conform to the unpack format

a4 x a4 x a5 x2 a3 x3 a3 x2 a18 x a3 x a3 x a
[download]

Something similar would have to be devised for the $details in record-starting lines. Also, the else-branch will need to test $details against /^\*\*/ to tell apart lines with course details from those with constraints. You'll need a few variables to store some state when you detect a new record, so you can access it in the following iterations on the detail lines. The logic is simple enough that you need not and should not use gotos.