To copy a form from one application to another you copy the form definition.
1. Open the original form in the form editor.
2. Click on the Form Definition icon highlighted in red below:
3. The form definition opens as follows:
4. Press CTRL and A to select all the text in the form definition, and CTRL and C to copy it.
5. Go to the other application, and create a new form.
6. Open the form definition (like in step 2 above) and erase all the text.
7. Use right-click Paste, or the keyboard shortcut CTRL and V, to paste the original form definition.
8. Click on Apply and then save the form.