Validate the excel header

You can read data from Excel files using the Excel Tools plugin and its associated smart services. For more information, please refer to the following resources:

Excel Tools plugin documentation:  https://community.appian.com/b/appmarket/posts/excel-tools

The attached documentation for additional details
.[View:/cfs-file/__key/communityserver-discussions-components-files/11/readExcelByHeaders.pdf:320:240]

Hi [mention:c7ed152842da4892ba88b9d946100b8f:e9ed411860ed4f2ba0265705b8793d05] 

Use constant for storing the column names.
I hope this is what you are expecting.

a!localVariables(
  local!columnNames: {
    "SAP  Number",
    "Qty",
    "Spare",
    "Price",
    "Delivery Date",
    "Remarks"
  },
  local!excelDataSubset: readexcelsheetpaging(
    excelDocument: ri!excelDoc,
    sheetNumber: 0,
    pagingInfo: a!pagingInfo(startIndex: 1, batchSize: 1)/*batchsize is 1 Because we need only first row from the excel to validate, which will be column names*/
  ),
  local!columnsNamesFromExcel: index(
    local!excelDataSubset,
    "data",
    "values",
    1,
    {}
  ),
  reject(
    a!isNullOrEmpty,
    a!forEach(
      items: local!columnNames,
      expression: if(
        contains({ 1, 2 }, fv!index),
        /*mandatory check for first two columns*/
        if(
          tostring(
            index(
              local!columnsNamesFromExcel,
              fv!index,
              ""
            )
          ) = tostring(fv!item),
          null,
          concat(
            "Invalid header at A",
            fv!index,
            ", Expected header is '",
            fv!item,
            "' but it has: ",
            index(
              local!columnsNamesFromExcel,
              fv!index,
              ""
            )
          )
        ),
        if(
          a!isNullOrEmpty(
            index(
              local!columnsNamesFromExcel,
              fv!index,
              ""
            )
          ),
          null,
          if(
            tostring(
              index(
                local!columnsNamesFromExcel,
                fv!index,
                ""
              )
            ) = tostring(fv!item),
            null,
            concat(
              "Invalid header at A",
              fv!index,
              ", Expected header is '",
              fv!item,
              "' but it has: ",
              index(
                local!columnsNamesFromExcel,
                fv!index,
                ""
              )
            )
          )          
        )
      )
    )
  )
)