Missing info


I made a form and i have made changes and added extra columns etc... How would I send the same form but it would only show whats missing on the row they assigned too. So if they missing info in 2 cells the form would only show those 2 cells asking for them to complete it.

The reason being we generate a document and all cells must be provided as we use the "Required " but sometimes we have to add a new column and add it to the form but then want to send the form but only ask for whats missing.

Hope i made this sound right. Any help here please would be great.