You can manually add custom fields in qTest Explorer and map them to the corresponding fields on VersionOne.
Click the Add Custom Field link on the Fields Settings form. The form displays.
Enter field name. The field name must match the corresponding field name in VersionOne.
Enter System Name. The System Name must match with the corresponding System Name in VersionOne.
Select Field Type and click Save.
When you select Field Type as drop down, the List Type field becomes editable
You must enter a List Type that matches the corresponding List Type in VersionOne.
Click Get Value to get the list of Accepted Values for the corresponding List Type from VersionOne.
Click Save and the newly added custom field will appear on the Fields Settings form.
You can edit or delete custom fields that are created in qTest Explorer.