What Is The Treatment For Cold And Cough?

My 2.5 year old daughter has had a cough for almost 3 months now. We have been to the doctor around 8 for this, but everytime I'm told that it's a cold and has to run it's coarse. But it really only comes on when she runs, laughs a lot, or at night when she sleeps. I finally got to talk to her doctor the last time and he put her on a inhaler to test out for 3 weeks. At times it seems to help, but never really takes away the cough fully. I think he said we wouldn't know till the 3 weeks if it would work. of course she got a cold this last week, which looks way different than just the cough she's had for the last 3 months.. She had a fever, runny and stuffy nose, and the cough with this cold, way different than the cough she's had for the last 3 months. We go to her doctor on Wednesday and I want to make sure that they check her out and if there is anyway she has RAD? Is there a test I can ask for to make sure it's "just a cold" like i've been told. My poor baby and I both have bags under our eyes from lack of sleep. Any help you can give would be appreciated.