I am writing a program in Excel and I want to be able to pull information
from a table, which is 15x11, in another worksheet. In the program,the user
enters a value which will corresponds to a specific column in the table (so
this is my x-value). Each column contain a series of increasing numbers. I
want the program to interpolate within that specific column entered by the
user, to another value that the program had calulated previously, then
reference that to a value in the first column (y-value).

Example:
A1=4.5
B1=545

3.0 3.5 4.0 4.5 5.0 5.5
0 |
1 |
2 |
3 523
4 - - - 555
5

I want the program to return the value of 3.69.