Creating an SMS workflow rule to include expressions

[TerriKCC]

Hi, I have created a workflow rule that, when a new row of data is entered, the designated staff member receives a text. Right now it is a static message. I am hoping to create a dynamic sms message with an expression like this.

CONCATENATE("Hello, you have a new referral! Patient’s name is: ", [Patient Name], ". The Case Urgency is: ",[Urgency], ". Primary Contact is: ", [POA/Primary Contact], " and Contact Number is: ", [POA/Primary Phone], “. Mahalo!”)

All I can see is options in MESSAGE CONTENT > Body, Body Template, Body Template Data Source. How do I enter in the expression above? Thank you!