If you are using the Standard TouchPoint Universe for a query, you can create details to pull First Name and Last Name from Subject Name.
Create a variable (you can call it First Name Detail or something similar). You will need to have a merged object in your report, preferably a Subject ID. Change the qualification to detail and use the merged object as the associated dimension. From there, use the formula below. Repeat steps for Last Name Detail.
=Right([Subject Name];Length([Subject Name])-Pos([Subject Name];" "))
=Left([Subject Name];Pos([Subject Name];",")-1)