fill between two end values and a center point

Hello ,
excel can fill data in with 2 or more values given.
example 1,2 will fill 3,4......x depending on the amount you want.

I want to fill between two end values and a center point

These are xy plot values
X, Y
21.0, 11770
:
:
22.0, 11290
:
:
23.0, 10840

After graphing and trending I want the points along the trend line for .1 graduations 21.0, 21.1, 21.2..................................22.9, 23.0
and 11770.....................11290................... .......10840...

This is a fine characterization of a thermistor (temp vs resistance)


There is a tool Digdb that claims to do this for a price.

anyone here know how to do it.

thank you in advance

I was frustrated that excel didnt give a explanation , that I could find.
I didnt want to pay for an add in, for 1 function. So I took on the task
and found my answer.

Which I can share if anyone wants the steps to do so , or has a need to fill between numbers.

golfcents