>>>You can try this in lostfocus

*lostfocus
>>>this.value = substr(this.value,1,1)+;
>>>        padl(val(substr(this.value,2)),5,"0")

Inputmask would be something like "A99999" and format "!".
>
>>Change lostfocus code to :

this.value = substr(this.value,1,1)+;
>>        padl(substr(trim(this.value),2),5,"0")

Cetin

TRANSFORM("@L 999999",XXX) pads XXX representation with zeroes; I would try to use that instead of PADL().