namespaces with the "using" directive

i have been searching online for a while with this question... all to no avail.

if you are writing a module that modifies existing software then in your module classes you implement some of their code:

using existingSoftware.helperClass;
using existingSoftware.DAL;

namespace MyModule
{
    class moduleHelper
    {
     }
}

if the existing software changes to the point of having a namespace change, is there a way to import the namespace into your module based on if the namespace exists? somthing like this:

using existingSoftware.helperClass;

if(existingSoftware.DAL != null)
    using existingSoftware.DAL;

else if(existingSoftware.LinqDAL!= null)
    using existingSoftware.LinqDAL;

namespace MyModule
{
    class moduleHelper
    {
     }
}

The point of this question is so that i don't have to maintain two code branches where one imports "existingSoftware.LinqDAL" and the other imports "existingSoftware.DAL". I have already abstracted till it's just one line of code diffrence it's just annoying that it has to be done that way.