If you have the bismark tip, then yes, but be careful how much you squeeze in or you'll break the cupcake.
Your other option is to use something like an apple corer and take out a center core and fill that. Some will put a bit of that removed core in for the top, before icing. But I'd just ice right over top. If you watch Cupcake Wars you'll see that most of them use the center core and just fill and ice.