Trap illegal date in trigger

[Tom Byars]

I'm importing data from a ms database into mysql. One of the ms columns is an integer type which represents a date in the form (year-1900)*10000+month*100+day. e.g. 20120907 is of the form 1120907.

I want to change this to date(msIntDate+19000000) before it's inserted in to the mysql database. I've tried trapping it in a before insert trigger but mysql raises a invalid date error before the trigger is called. Any way of doing this?

PS I need to be able to import the data from the ms table in the form

select * from msTable

because the msIntDate is spread throughout many different tables which have many columns so it's not just a simple case of importing it as msIntDate+19000000.