I'm trying to replace strings in a sheet. It works just fine for all my text values, but I have a problem with functions. 

I have phone numbers that are imported but unfortunately, I get a `=+` placed in front of them.

So the values are not 555-8181, its =+555-8181.

When I try to use for example Replace it doesn't work, likely because the values are stored as a function, and not a string, but I can be wrong.

Any hints on what to do?

Example of what I have tried:

```
function RemoveErrorInPhonenumber() {
  var sheet = SpreadsheetApp.getActiveSpreadsheet().getSheetByName("SheetWithNumbers");
  var range = sheet.getRange("Z:AG");
  var rngA = range.getValues();
  for(var i=1;i<rngA.length;i++)
  {
    rngA[i][0]=rngA[i][0].toString().replace("+", "");

  }
  range.setValues(rngA);
};

```