Adding Validations in "User fields" of Work order operation

Hi Team,

Is there any way through which I can put validations in the fields which we configure for Work order Operations (Task Lists -> Operation Data -> Define User Fields) ?

For example, i need to have validations for some set of values for a text field.

Need to have validation for "time format" for a text field...

Is there any exit/BADI available for validation?

Thanks and Best Regards

Anish