Have you read through this topic: http://forum.katalon.com/questions/using-variables-in-test-objects. In your case you will need to adjust the code a little bit by using xpath instead:
lnk_EditEvent.findProperty('xpath').setValue(//div[@class='cx-item-md-3′ and contains(text(), CheckInTimestamp)])
lnk_EditEvent.findProperty('xpath').setActive(true)
In the next release, this will be a native support so that you won’t have to spend so many efforts in writing code like this.