Export to Excel missing leading zeros

Hello,
 
When our Flat report is generated, it is showing leading zeros on a column. When we attempt to Export Excel then Excel doesn't show leading zeros.
 
Our report has a csv source that we pull down from S3 that has the following format:

[
  {
    "hiddenHeader": {
      "type": "hidden"
    },
    "Submission Id (Form Attributes)": {
      "type": "string"
    },
    "Routing Number": {
      "type": "string"
    }
  },
  {
    "Submission Id (Form Attributes)": "12345679",
    "Routing Number": "90410311"
  },
  {
    "Submission Id (Form Attributes)": "039960648",
    "Routing Number": "0038192134"
  }
]

• They show up correctly in the Flat report.
• Also, the csv export shows them correctly when opened in a text editor
• However, the Excel export loads those columns as numbers and therefore it removes leading zeros

 
Flexmonster Version: 2.9.43 
 
Workaround: Our customers can obviously export a CSV and important it into excel. Then define each column type, but it seems like Flexmonster should do this since it knows the types and displays them accurately.
 
Thanks,
Patrick