See Character-based Alignment in a Table Column in the CSS Text Module Level 4 specification.
For example, td { text-align: "." center } might render the following table:
+---------------------+
| Long distance calls |
+---------------------+
| $1.30 |
| $2.50 |
| $10.80 |
| $111.01 |
| $85. |
| N/A |
| $.05 |
| $.06 |
+---------------------+