Spring-Damper variable force input

I am working on a very basic model of a viscoelastic material under tensile load. I started by creating a basic spring damper model with integration and gain blocks and then tested this by applying a step input.

Rather than a step/ramp etc load I was hoping to a apply variable time dependant load based on real data from experiment. I have two columns in excel 'time' and 'force' and want to apply the force to my spring damper model according to the times from my data. i.e 0N at 0s, 10N at 3s 20N at 7s etc etc etc

I have tried importing the excel data and saving it as a .mat file and then running that in my model with a from file block but that hasn't worked.

Has anyone else tried this? I'm sure its a simple task but I'm not normally a simulink user.