How do I get Excel to split a sequence of delimited values in a cell over multiple cells?

 |    A   |   B
1| 1 2  4 |
2|        |

Split over /\s+/:

 |    A   |   B
1| 1      |
2| 2      |
3| 4      |

This is in a pivot table, so I want the pivot table's mechanism to take the split in account, and consider it as if the data came this way from the datasource.