I am using the nested functions below

"=if(vlookup(1, GRID, 3,false) = 0, (1, GRID, 4, false), (1, GRID, 3,
false))"

i.e for the row with the digit one in its first column return the value in
the third column else if empty return the value in the fourth column.

my problem is i am repeatedly using the line above exactly only changing the
value i am searching for (1 in this case ))

so ideally i'd like to do something like

define myformula(X) = if(vlookup(X, GRID, 3,false) = 0, (X, GRID, 4, false),
(X, GRID, 3, false))

is this possible?????????