The CPAN documentation says :
Multi-line or multi-valued parameters may also be defined ala UNIX "here document" syntax:
Parameter=<<EOT value/line 1 value/line 2 EOT
You may use any string you want in place of "EOT". Note that whatever follows the "<<" and what appears at the end of the text MUST match exactly, including any trailing whitespace.
Alternately, as a configuration option (default is off), continuation lines can be allowed:
[Section] Parameter=this parameter \ spreads across \ a few lines
Have you tried either of those? (trying to fudge something else is probably hard work....)