Display the Drawing toolbar and choose the Line tool, and draw
the line directly on the worksheet. If you want a VBA solution,
use code like the following:
Dim WS As Worksheet
Set WS = ActiveSheet
WS.Shapes.AddLine beginx:=Range("C3").Left,
beginy:=Range("C3").Top, _
endx:=Range("G3").Left, endy:=Range("G3").Top