How can I create a custom report with the following information in it: 

Computer Name, Primary User, IP, Machine Type and Model, and Last Login.  

Open the Resource Manager for a managed computer and check out the Inventory Tab. Look through the Basic Inventory tables (all AeX AC blahblah) and the Inventory folder tables, Hardware (AeX HW blahblah), Software (AeX SW blahblah), Operating System (AeX OS blahblah) and User (AeX EU blahblah). You can see all these tables from inside the Simple Report builder.

Reports Tab- right click, select New Report to open the Report Builder. The default report type choice is 'simple report', leave it.
Data Type- select Computer
Fields- Here's the list of AeX tables.

For your info, select:

AeX AC Identification table- Name, Last Logon fields
AeX AC Primary User- Primary User field
AeX AC TCPIP- IP Address
AeX HW Serial Number- computer type, machine model

Note! Highlight only the field you want, not the table name.

This will display only this info for all your Altiris Agent computers.

To filter it to a naming convention OR IP address range, use the Criteria link.

Select the table to filter from the dropdown:

For name, select AeX AC Identification table, set the condition (LIKE) NY12%. All computers with names that start with NY12 will be returned. (% is the SQL wildcard)

For IP Address, select AeX AC TCPIP table, set the condition (LIKE) 172.16.42.%. All computers with IP Addresses with 172.16.42.xxx in them will be returned.

The Sort Order works like the Criteria. Select the table ie, select AeX AC Identification table for sort by name, then ascending or descending.