Javascript command to change a tex-field's format

Hi.

In acrobat pro XI. we can open the field properties dialog and change the format of the text field to Number,Percentage,Date,Time,Special,Custom.

I need to do it but with an acrobat javascript command, I need to do change some fields to a Date format with this custom structure: dd/mm/yyyy.

Is there a javascript commmand that does it? Something like:

var f = this.GetField("testfield");

f.setFormat("Date","dd/mm/yyyy");

Thanks