Hai daniel,
What is the input and output?
1) Do you need displacement or velocity or acceleration response?
2) Are you interested to solve using mode superposition method or full method or reduced method?
Yes, It is possible to carry out the frequency response analysis.
One better example is there in verfication manual. If you unable to trace out, e-mail me, I will e-mail you the path in help.
Regards,
elogesh