I come across files all the time where the designer used multiple blank spaces, or even separate text boxes to align the period after the numbers in a numbered list in their InDesign document. It’s a royal pain in the ass to fix, and it actually is a lot more difficult to do than just doing it the proper way to begin with.
To align the punctuation in numbered lists, the first thing you do is NOT type numbers. Simply select the items in your list and click the Numbered List icon in the Control Bar (see image above). This will add the numbers for you.
To align the punctuation, Option + Click the same Numbered List icon in the Control Bar and adjust the Alignment of your list to Right Justified.
Next, click the Preview checkbox in the lower left corner of the dialog box so you can see your adjustments updated live, and adjust the Left Indent amount until there is a sufficient amount of space after the numbers and before the text of the list.
Finally, adjust the First Line Indent amount by a negative number until your satisfied with the look of the list. The amounts in the screenshot above is what I used to achieve the fixed list on the right.
The beauty of doing it this way is that you can go back later and make adjustments to all your lists at once, no hitting the space bar multiple times, no setting multiple tabs, no hassle!