Right-aligning one table cell removes intentional spacing from other table cells

I have a multicolumn table. I want the 1st column to be right-justified and the 2nd column to be left-justified. I can't do this so I have to adjust each cell individually. I also want some of the text in the 2nd column to be indented, so I added spaces in front of the items. If I click right justify on a cell in the 1st column, it removes leading spaces for items in the 2nd column.

Before:

|   a1|b1      |c1    |
|   a2|  b2    |c2    |
|a3   |  b3    |c3    |

After:

|   a1|b1      |c1    |
|   a2|b2      |c2    |
|   a3|b3      |c3    |