C# syntac is like C++. You have new features in C# that aren't in C++ (otherwise why create a new language
If you've done things in C++ already, C# shouldn't be that difficult (unless you never used Visual Studio).
In fact you can do anything with most languages. In that case C# would be the industry standart. But you can also do it easyly with C++, Delphi or VB... It depends of your skills/budget.
For my part for those kind of projects, I use Delphi because making great GUI with Delphi is really easy and I'm fluent in Pascal. And with Delphi 2009 you have built-in Office 2007 GUI objects