This might work:
Put a "named object" or field at the extreme left and right of your layout.
Use go to object or go to field and specify the extreme right object/field to scroll to the right.
Use another go to field or go to object to leave that object and put the cursor in a place where the user expects.
Do the same but specify the left object to scroll the other direction.
I know it's clumsy, but I can't think of any alternatives.
I tried going to a field -- and that did scroll -- but left a lot of collateral damage on the screen: multiple text boxes selected.
I can't get a named object to work. I created a button that does nothing and used the info panel to name it righto with no quotes.
With the go to object script command I'm referring to it as "righto". Is that correct, with the quotes? Unfortunately it doesn't scroll right.
"I tried going to a field -- and that did scroll -- but left a lot of collateral damage on the screen: multiple text boxes selected."
Multiple text boxes? That's not possible. You can only edit one field at a time. Neither "go to field" nor any other method scripted or manual can select multiple fields. If the script leaves the cursor in a field, the field borders may change appearance to show that you are editing the field if the "Show field frames when record is active" option is selected for your layout. Since this is the default setting for a new layout, it probably is. I predict you'll see exactly the same thing if you just enter a field manually by clicking on a field or pressing the tab key. If you don't want that affect, you can either change this setting for your layout, (It's a check box in Layout Setup...) or try Go To Field  without any field selected.
I just tried using go to object to set the focus on a named button and haven't had any luck with that either.
Thanks for that explanation. It was a weird effect to see the field borders appear on three text boxes.