I would hope that any PSA licensed installer should be able to do this but chances are they will not.
Ring 3 local companies and get prices and if they tell you that it can't be done etc etc stay away from them.
It's not a big job but will involve running a cable from your alarm panel to your broadband modem and fitting an ata box if you do not already have one.
DirectSecure in Lucan did this for us a few years ago, we inherited an Eircom phonewatch HKC Alarm and they fitted a dialler on for us for about €120 I think. We find it great. Hope that helps.