How can I import multi-response data from Excel to my dashboard?

Hi,
I just transitioned a survey that we have been doing in another platform to Qualtrics. The client wants the historical data combined with the Qualtrics data in a dashboard. I imported the historical data to the dashboard from Excel. Everything is going smooth except the handling of multi-select question. The excel file has a separate column for each choice in the multi-response question and I cannot map it properly with the Qualtrics survey. What should I do? How can I format the multi-response question in Excel so I can map it correctly?