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FAQ/How to Write to an Existing Excel File.md

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+# Write to an Existing Excel File
+### Enumerate the Excel File
+```powershell
+$ExcelPkgFile = Open-ExcelPackage -Path  "C:\Test\file.xlsx"
+```
+Contents of file.xlsx:
+![ExcelFileContents](/images/FAQ_Images/ExcelFileContents.png)
+### Enumerate the Worksheet to View or Modify the Data
+```powershell
+$WorkSheet = $ExcelPkgFile.Workbook.Worksheets["sheet1"].Cells #open excel worksheet cells from worksheet "sheet1"
+```
+Visual of Data Structure:
+![DataStructureExcelPkg](/images/FAQ_Images/DataStructureExcelPkg.png)
+
+Modify a specific value by accessing row/col like a 2D Array:
+```powershell
+$WorkSheet[1,4].Value = "New Column Header" #Starts at index 1 not 0
+```
+