I wandered over to Critical Path's website to look into this. Unfortunatly, they require user registration to look at their support documentation, so I'm unable to look.

However, the issue you are attempting to resolve is definitely specific to this software. I'm not sure how Perl would interact with it. Perhaps there is an API it needs to make use of. Maybe there is an SDK. I'm not sure, but your best bet will be to dig through the Critical Path documentation, or to even contact their tech support.

Just as a side note -- and this can become a religious topic, I just want to make sure it's brought up so you can choose which side you want to be on -- having logins disabled after 3 attempts may be asking for trouble with denial of service attacks. But if that doesn't concern you, by all means continue :-)
-Eric