Hoi,
SignalExpress textbox is not suitable for this, you cannot bind the text to that particular parameter (see the screenshot below). However, there is a way to add unique description to each log, with marking ‘Prompt for title/description when log is created’ checkbox at the Recording Options/Log Summary tab (another screenshot for this as well).
SignalExpress is marketed as a quick testing/measurement system, for more complex and robust application we recommend using LabVIEW.
I hope this is a possible answer to your question.
Regards,
Peter