By TextBox you mean the TextBox from the 'Drawing' toolbar ? if so, you do it something like this:
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<SPAN style="color:#00007F">Sub</SPAN> ShapePicture()
<SPAN style="color:#00007F">Dim</SPAN> Sh <SPAN style="color:#00007F">As</SPAN> Shape
<SPAN style="color:#00007F">Set</SPAN> Sh = Sheets("Sheet1").Shapes(1)
Sh.Fill.UserPicture "D:\My Documents\My Pictures\DSC00090.JPG"
<SPAN style="color:#00007F">End</SPAN> <SPAN style="color:#00007F">Sub</SPAN>
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If you want to resize the shape to adjust the ratio of the picture, that requires a bit more work:
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<SPAN style="color:#00007F">Sub</SPAN> ShapePicture2()
<SPAN style="color:#00007F">Dim</SPAN> Sh <SPAN style="color:#00007F">As</SPAN> Shape, Pic <SPAN style="color:#00007F">As</SPAN> IPictureDisp
<SPAN style="color:#00007F">Set</SPAN> Pic = LoadPicture("D:\My Documents\My Pictures\DSC00090.JPG")
<SPAN style="color:#00007F">Set</SPAN> Sh = Sheets("Sheet1").Shapes(1)
<SPAN style="color:#007F00">'Resize the picture, keeping the Width constant</SPAN>
Sh.Height = Pic.Height / Pic.Width * Sh.Width
<SPAN style="color:#007F00">'Clear Pic from memory</SPAN>
<SPAN style="color:#00007F">Set</SPAN> Pic = LoadPicture("")
<SPAN style="color:#00007F">Set</SPAN> Pic = <SPAN style="color:#00007F">Nothing</SPAN>
<SPAN style="color:#007F00">'Load the picture</SPAN>
Sh.Fill.UserPicture "D:\My Documents\My Pictures\DSC00090.JPG"
<SPAN style="color:#00007F">End</SPAN> <SPAN style="color:#00007F">Sub</SPAN>
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