In graphics mode select your Text List Object and then click the suitcase icon in the tool bar and choose the Selected Objects… item. When the Blueprint sheet opens look at the line "$TextListColumns" and add
<align:right> after your variable name and within the quotes. When finished click the Update Form button at the bottom and your text should be right aligned. Here is what my test Blueprint looks like with this added to the variable name.
This can also be added if you use the Constructor to create you List. After entering your field or variable click on the tag icon at the top of the Constructor window and select the alignment tag you want to use and the List will be created with that alignment for that column.