This is actually very easy to do.  You need to add a recieving data connection

Click on Tools>Data Connections
Click on the Add button.
In the first page of the wizard select Receive then click next
Select Sharepoint library or list, then click next
Enter the URL of the site that contains the issue list and then click next
A list of all lists for the site will be displayed.  Select the Issues list
and click next.
All columns for the list will be displayed.  Select the ones you want to
retrieve data from, then click next
Enter a name for the data connection and click finish.

If you want to add or update a list you will need to connect to Sharepoint's
webservices for submitting data.  The wizard will step you through also.  
This time you're submitting data and you're connecting to a web service.

HTH.