InfoPath Dev

Hi, 

I have a form based on an XML schema. Below is part of the actual XML file. What I want is , when the custom field value name becomes "Payment Term Exception", I want to change the field type from "Text Box" to "Drop-down List Box" and set the values for the list box dynamically. is it possible ?

 Thanks 

 <CustomFieldValueSet name="AccountNumber">
                <CustomFieldValue>
                    <Value>1001120006</Value>
                </CustomFieldValue>
</CustomFieldValueSet>
<CustomFieldValueSet name="AccountObjectLink">
                <CustomFieldValue>
                    <Value>VC11</Value>
                </CustomFieldValue>
</CustomFieldValueSet>

<CustomFieldValueSet name="Payment Term Exception">
                <CustomFieldValue>
                    <Value>free form</Value>
                </CustomFieldValue>
</CustomFieldValueSet>