You can also use a finished Injector. If you want to make your own then look at youtube videos. But it´s just C&P and not coding.
Here:
To create the Injector you need Visual Basic. I use VB 2008.
The Code is under the video.
little HowTo:
1.Download Visual Basic 2008
2.Install it
3. Open it and make a new "Form File"
4. the name is not important
5. double click on the form
6. now paste the code below
7. go to the form create 2 textboxes and 1 timer
8. now it´s finished but you can design your Injector on the right side is a property box with this you can design it.