Create JIRA dashboard using 3rd party data source

In one of my client organization, they are using JIRA for PM. However the Test cases are all in a custom built application which they don’t want to let go. Is there any way I can connect the custom developed Test tool with JIRA so that JIRA dashboard can also be made on data available in this 3rd party. For e.g. Want to show No of Test cases associated with a story, test case pass / fail rate.

Basically to use JIRA as a common reporting / dashboard tool.