Using Validator

[Babe Ruth]

I am trying to make a date format validation in which the a value of the cell must be in (mm/dd/yyyy). If a cell will be typed for example (abcdeef), it will not be printed in the cell. There will prompt a message that it is not the correct format.

I used this code

$row_count = 7;

$valformula =& $workbook->addValidator();
$valformula->allowBlank('true');
$valformula->setFormula1('(CONCATENATE(MID($row_count,1,2),"/",MID($row_count,4,2),"/",MID($row_count,7,4)))');
$valformula->setError('Invalid Date Format','Please fill correct format (mm/dd/yyyy)','true');

$worksheet->setValidation($row_count,1,$row_count,1,$valformula);

There is an operation time-out when I run it. How will I used the Spreadsheet_Excel_Writer_Validator. How will I use correctly the fomula for validation. I cannot see any documentation or samples regarding the usage of Validator