Hide fields in customized URL query string

Is it possible to change fields to hidden in the URL string, that are not normally in our forms? I have 7 items that have preset values and can only be requested for a short time each year. Instead of creating 7 more forms (based off the our primary form) I would like to if it is possible to build the url string with these preset values and hide the fields, so that they cannot be modified.

For example, you want to set the Length to 72, yet when they open the form they do not see this field... https://app.smartsheet.com/b/form/6145a2c33c4e42e68bf53900e4a4845b?Length=72