Resolve assembly references from another folder

Solution 1:

You should first find the folder where theses dlls are installed then use AppDomain.AssemblyResolve to hook assembly resolution and try to load the requested assemblies from this folder.

It will look something like this (not tested, and you need to check what args.Name contain exactly, could contain the version and the strong name along with type name) :

var otherCompanyDlls = new DirectoryInfo(companyFolder).GetFiles("*.dll");

AppDomain.CurrentDomain.AssemblyResolve += (sender, args) =>
{
    var dll = otherCompanyDlls.FirstOrDefault(fi => fi.Name == args.Name);
    if (dll == null)
    {
        return null;
    }

    return Assembly.Load(dll.FullName);
};