Stop Repeating a Variable in one Function

[0123ren]

OK, Im sorry if this question has already been asked but I couldnt find the answer anywhere. I want to apply a particular formula to a column which also takes a variable from the column to the left of it.

A B
5 1.5 =A5*2
6 2 =A6*2

etc.

This is what I want but there is also another variable present in the formula in column B from say Cell A2, this is simply one number which I want repeated throughout the column without excel automatically taking the number from the row below it when I fill down. Does anyone know how to program excel to allow one variable to be static whereas another variable in the same function can take be taken from each respective row.

I hope I have explained this OK, I await any replies and thank you in advance.

 

[Richard Schollar]

I *think* you mean you want a static reference:

=A5*2 + $A$1

copied down - $A$1 is fixed (ie it will always refer to cell A1).