If you are wanting to 'jump in' to a Fibbonacci sequence midstream and find the next 5 numbers by formula, then you could do the same thing perhaps this time downwards to prepare a lookup table.
e.g Type in 0 in cell A1, type in 1 in cell A2, type in formula =A2 + A1 in cell A3 and copy it down the column as far as you need. Give this table a name say Fibtable.
Chose a cell to type in a starting Fibbonacci number, say cell C3. In cell C2 enter the formula = =VLOOKUP(C3-1,Fibtable,1).
Then in cell C4 type in the formula =C2 + C3. Copy this down to 5 cells below (the next five fibonnaci values).
When you type in any FIBBONACCI Number (that exists in your table up to 5 from the bottom) in cell C3 then cells C4 to C8 contain the next 5 values. You can hide your original Fibtable now.