Update columns when data is invalid

Hi All,

I got two columns DEATHDATE and STATUS

I have to update STATUS Column as INVALID when data in DEATHDATE column as follows
Example of INAVLID DEATH DATE : 1221, 12xt88,12#10, 1, ABC, #@ , etc

Do nothing when the DEATHDATE is VALID like

Examples of Valid/accepatable DEATHDATE:     91212, 09122012, 091212 ,******,********, 000000,00000000

How can i achieve this.