Forms :: Command Button To Add New Record In Subform

I am designing a database to manage hospital patient data. I will have to enter info at various points, e.g. when a patient is referred, admitted, discharged...

So for example, I have a main form with the patient's name and two subforms, one with the referral details (e.g. date, name of referrer...), and one with the admission details (e.g. date, diagnosis). They are linked through Parent-child links to the main form by PatientID. So, when I enter a new PatientID in the main form, the ID in the subforms is automatically added/synchronized.

However, I would like it not to be...since not all patients that are referred are then admitted. Therefore I would like to have a command button in the main Form that allows me to control when a new patient record is added to the admission subform. In other words, I would like an "Add a new Record in the admissions subform" button, which then creates a new record, with matching PatientID in the admissions subform (and in the related table). Is this possible???

I have tried using the command button wizard but it either requires a record to be already present in the subform, or it takes me to the first record of the form, and not the matching PatientID one.