Excel - If cell A = 'yes', enter 'x', else use data validation to restrict entry

I am trying to combine an IF statement with data validation in MS Excel.

I have a row of cells (A1, A2, A3... etc).

If the value of these are "No", then I want the values in the column below to be "x". If the values are "Yes", then I would like the values below to allow entry in date format only.

Is there a way I can do this by entering an IF statement into the Data Validation 'custom' setting?

Appreciate any information.