Loops In Vba

how can i make a loop throught the G colum and to check if the cell before the currect is bigger/ lower or equal to the currect cell. and if its higher then an arrow will be shown '^' if its lower an upside down arrow will be show 'v'
equal will show -> arrow. example:

G2 = 200
G3 = ^ 300
G4 = -> 300
G5 = v 209

so how can i change the G3 to G4 G5 etc.. in a loop in the: Range("G3").Select command? and i need to change the

.Value = "=$G$2"
to
Value = "=$G$3"
Value = "=$G$4"
etc...
in 2 places................