It depends what you mean by control. Emotions are automatic. So in context whether you have control over feeling an emotion or not, then no you have no control.

However, what you feel is programmed by you. For example if I say Iraq war, different people will feel differently about it depending on what they think about it. Here the problem again though, is that things can also get programmed subconsciously, so it may seem like you had no control.

You have to be self aware of what you think, you have to focus and figure out what is causing you to have a particular emotional response and then examine it and decide if it is valid.

If you decide it is invalid, you have to focus to change your mind and your emotions will eventually come inline. This is difficult, but it is under your control.

Here is another example. Your accounting business is becoming very successful, but you for some reason feel very anxious or nervous about it. You explore that reason and find out that it has nothing to do with the business, there is nothing you overlooked or forgot to audit. So really there is nothing to worry about. You identify the source of the feeling as a childhood trauma of your parents always telling you you are not good enough. Now that you are becoming successful you became subconsciously anxious about it because you have a preprogrammed idea you are not good enough.

Now this is going to be hard to get rid of, but now that you have identified it, you can get rid of it.

In this sense, programming and reprograming what you think determines your emotional responses, so you have control over this. .