Setting the property value priority dynamically in the Business Central Designer

Issue

• How to set the property value priority dynamically in Designer?
• We want to set the priority value in a User Task in Designer dynamically by using a process variable.
• When we set a expression like this in priority field, #{processVariable.priority} the Designer gives us a warning "Must be a positive Integer".
• Is there any way to set the priority to a task dynamically?