Hi Karim Es.
If there is no cost, then settlement or not-settlement will not make any difference. But what I understand is, in your case, you want to plan the costs but want to keep the actual costs zero. Am I right? Why do you want to have this scenario?
There might be other ways of doing this but possibly one of them will be using an activity type with a small amount of rate (SAP does not allow you to enter 0 on activity rates) while actualizing the order. So planned amount will use a separate activity type than actuals.
I hope this helps.
Cheers
Savas