creating formula.

[ravi.1225]

Hi
I have written one formula in excel. I will use that formula very day.

Now my requirement is I want to add this formula in excel function.how to achieve this.

Another requirement is that i will use this custom formula in different places,in this case I want to edit the column from A to C.
How to change the column in custom function which made as global

[Olly]

To be clear:

You want to write a UDF (user defined function) to use instead of a complex formula, which you already have. You want this UDF to be able to accept relative references. And you want to be able to use this function in all your workbooks.

Is all this correct?

If so - first of all, please share the formula.
Then once the UDF is written, the best option will be to create an addin which contains it.