Hi,
Yes, you can give a designation of a Director to your employee.
If the employee designated as "Director" even though he is not a member of the Board than it may fall under "Deemed to be Director of the Company" under Explanation (1) of Section 303(1)if Board acts in accordance with his instructions or he holds himself as Director by signing the Balance sheet as 'Director" For signing part, he can continue to Sign IN ADDITION TO BOARD OF DIRECTOR AND CS thus complining with Sec 215. But do not use designation as Director.