Insert scanned drawing of a person into a frame of given dimensions on photoshop

I am currently working on painting a religious icon/painting, of about 7ft in length, and about 3ft in width. The shape of the icon will be rectangular from the bottom, and semi-circular from the top. The drawing will be a picture of Saint Brendan. I have the exact dimensions of the wooden frame of the icon, and a scanned copy of the hand drawn drawing of St. Brendan. I want to see how will the drawing fit into the icon, since the drawing is created using a smaller scale (fitted on approximately an A4 paper). In case the drawing does not fit well into the icon frame, I will ask to "stretch" or "squeeze" the drawing (maybe by extending the arms, increasing the size of the head, decreasing the length of the legs, etc...). Descriptions of attachments: -"icon frame": which is the dimensions of the opening in the wall where the icon will fit. The red border is what's visible to the public. Around the icon will be a wooden frame of 3.5 inches. -"end result": this picture shows ideally how St. Brendan will look like in the end. The goal is to fit the scanned drawing into the icon frame as best as possible. -"st Brendan drawing": this is a picture of the drawing that needs to be fitted in the "icon frame", and eventually will be painted in colors. Ideally, I prefer to video chat or share screens with the designer to give live feedback since I am not sure how the end result will look like.