Shortcut for word document on iPad homescreen?

Yes, you can by using the Shortcuts app.

In the Shortcuts app:

1. Tap the "+" icon (upper right corner).
2. In the search field, type "Open file" and tap the 1st result to add the action.
3. In the action, tap the "File" variable (next to the word Open) and select your Word document. Leave the "Default App" field blank or tap it to choose Word.
4. Tap the ">" icon (lower right corner) to run the shortcut and make sure it opens your file in Word.
5. Return to the shortcut.
6. Tap the name of the shortcut (top center) and choose Rename to give your shortcut an appropriate name. This name will be the one you'll see on your Home Screen.
7. Tap the name of the shortcut and choose "Choose Icon" to select an icon and a color for your shortcut. This icon will be the one you'll see on your Home Screen.
8. Tap the ⓘ icon (bottom center) and tap "Add to Home Screen" to add your shortcut to the Home Screen.

Sorry about that. On an iPad the icon is at the top. Here is a screenshot of what your shortcut could look like (I used one of my Numbers file for the example) and I highlighted the Run button (black triangle icon):