acrobat - Modify character spacing in a PDF form field -

I'm trying to create a web app for filling out a PDF form for the program. I'm going to first configure my product in Adobe Acrobat, then fill a Java application with iText to fill all form fields through the user input from the web. The basic form I need to fill comes from the US government. They created form fields with the need to change the huge kernel values. However, there is no way to modify this value in Acrobat UI.

Do anyone know how to manipulate character spacing on the form field in Acrobat 8.0 for Windows? I can try to use iText to programmatically manipulate the kerning of the original document, but it would be much harder to believe that I have come to know: Carning called "comb" in acrobat Goes, and each form. The field is "comb". The strange thing is that when I look at the properties of the form field, this option is not checked, but the "search" is the behavior that I was trying to repeat.