Sorry, i misread that. I don't see any documentation on the Network Solutions site about Pear mail, so I cant really say for certain what the path to pear would be on their servers.
I know you say you have already asked their support, but they weren't very helpful, but if anybody will know what the path to pear on a network solutions hosted account is, it would be network solutions support
Through google i found a thread in their forums that seems to hint the path is:
/usr/services/vux/lib/php/
script-help-perl-php-asp-net-f50-what-is-the-path-to-pear-mail-php-t8304.html
But i have no way to verify this.