Office Scripts - How to use "RC" in a Script

Hello,

Yes, my script (French) is :

function main(workbook: ExcelScript.Workbook) {

  let conditionalFormatting: ExcelScript.ConditionalFormat;

  let selectedSheet = workbook.getActiveWorksheet();

  let range = workbook.getSelectedRange();

  conditionalFormatting = range.addConditionalFormat(ExcelScript.ConditionalFormatType.custom);

  const formula = '=EST.PAIR(LIGNE(LC))';

  conditionalFormatting.getCustom().getRule().setFormula(formula);

  conditionalFormatting.getCustom().getFormat().getFill().setColor("#e2eefa");

  conditionalFormatting.setStopIfTrue(false);

  conditionalFormatting.setPriority(0);

}

Formula in english should be : const formula = '=ISEVEN(ROW(RC))';

And the result is 

=EST.PAIR(LIGNE('LC'))  instead of =EST.PAIR(LIGNE(LC)) (the script adds quotes !?)

Thank you for your help,

Arnaud