We have found 2 software records in our database eligible for .ics to .pst file format conversion.
In Microsoft Outlook, you can drag a certain calendar file (for example .ics) to one or more post storage files (.pst) to import the data to it. You will have to change the list and tweak it a little, but this workaround should work and essentially achieve ics to pst conversion.
Another way would be to use some of the dedicated utilities specially designed to import calendar / contacts data to Outlook files.
ICS
Files with ics extension are calendar data in exchange format which is widely accepted in many personal information managers and e-mail clients such as Microsoft Outlook, or Apple iCal. It is an universal format for transporting calendar data and events from one program to another.
PST
A pst file extension is used for storage file format of Microsoft Outlook. PST file contains stored emails, calendars, contacts in one single file.