フレーム全体の行揃えを変更する

[JavaScript]

var frame = app.activeDocument.selection[0];
frame.parentStory.justification = Justification.rightAlign;

[VBScript]

Set app = CreateObject("InDesign.Application")
Const idRightAlign = 1919379572
Set frame = app.activeDocument.selection(1)
frame.parentStory.justification = idRightAlign

※参考(一部)
Justification.leftAlign //左揃え
Justification.rightAlign //右揃え
Justification.centerAlign //中揃え
Justification.leftJustified //両端揃