I use this to add a picture. Maybe you can pick out the pieces you need:
Option Explicit
Sub testme01()
Dim myPict As Picture
Dim myPictName As String
myPictName = "C:\test.jpg"
With ActiveSheet
With .Range("a1:b9")
Set myPict = .Parent.Pictures.Insert(Filename:=myPictName)
myPict.Top = .Top
myPict.Left = .Left
myPict.Width = .Width
myPict.Height = .Height
myPict.Name = "Pict_" & .Cells(1).Address(0, 0)
End With
End With
End Sub
I'm not sure if you want to fix the .width or the .height, though.
Manually, you could adjust its size/position by holding down the Alt key and
using the grab handles. The picture will snap-to the edges of the cells.