Scroll bar - to increment btwn MIN and MAX value.

Help,

I don't even know if this is possible;

Issue:
I'm looking to put a "scroll bar" in a cell, which could be used to increment between a minimum value, and maximum value (values in other cells). I would like to be able to identify the increment value (sometimes referred to: step size, or index).

Example: (cells and, value or item)

A1 = 100,000 (minimum value)
A2 = 200,000 (maximum value)
A3 = 5,000 (the 'increment' value, step-size etc.)
A5 = <the scroll bar>
A7 = the resulting value between min and max, as adjusted via the 'scroll bar'

It might be obvious that I want to use the A7 value, as a chart element.

Thanks for any help you can provide.

jay