OpenClinica uses XLSForm as well (and are a contributor to the ODK ecosystem by funding a major part of Enketo's development). They've added some custom functionality to XLSForm/Enketo that wouldn't be applicable to the wider ecosystem. Best to check with them for more details on their system.
You can create a form in Excel by adding content controls, such as buttons, check boxes, list boxes, and combo boxes to a workbook. Other people can use Excel to fill out the form and then print it if they choose to.