Custom "My Messages" Widget

Hello dear experts,

I need help in the following matter:

I tried to assign a custom "my messages"-Widget to the home screen similar to the one below:

In spro under the following path I can create custom widgets like the above but I don't know how to get on my home screen.

There aren' t shown in the configure page where you can assign widgets to your home screen.

I also tried to change one of the standard "my messages"-widgets but nothing happened.

I hope someone knows where I have to make the assignment of custom widgets like this.

Thanks a lot

Martin Kläser