ModelBuilder use of Variable in Output Filename possible?

Hello,

I've setup a model with a variable named Survey_Number, it is set as a parameter. I use this variable in a Select Layer by Attribute function. I then use Make Feature Layer and check it to Add to Display. I have a number of surveys I want query and I was hoping I could use the variable in Output Layer name of the Make Feature Layer function. Something like this:

Output Layer
select_by_survey_result_Survey_Number

Can you use variables to create dynamic layer names or output file names in this manner? Or do I need to just set the Output Layer as a parameter as well and manually change the name?