Use CSharpCodeProvider to build code at runtime

gistfile1.cs

using (var codeProvider = new CSharpCodeProvider())
{
    var parameters = new CompilerParameters { GenerateExecutable = false, GenerateInMemory = true };
    parameters.ReferencedAssemblies.Add("some.dll");
    var results = codeProvider.CompileAssemblyFromFile(parameters, fileList);
    if (results.Errors.Count > 0)
    {
        var errorString = new StringBuilder();
        for (int i = 0; i < results.Errors.Count; i++)
        {
            errorString.AppendFormat("{0}{1}", results.Errors[i], Environment.NewLine);
        }

        throw new DataException(errorString.ToString());
    }
    else
    {
        assembly = results.CompiledAssembly;
    }
}