Copying and pasting a portion of a slide to another slide

It's in the screenshot within a slide. I'm trying to grab a small portion of the screenshot and copy it. It doesn't do that as I'm editing the slide. 

I'm teaching a software application. Think of a field as First Name and another field as Last Name. The First Name field value in the screenshot is Walt and the Last Name field value is Hamilton. I'm try to copy the name Walt and paste it another slide that has a first name of John. Is that possible? If so, how do you grab the portion of the slide of that you want to copy?