Minimum distance between two numbers at all times (otherwise, please read, a tad complex?)

Good Afternoon All,

First time post.

I am building an excel program to make work life easier/quicker and all that good stuff.

I will try to explain my aim as simply as possible (hopefully not confusing to all including myself!).

First, I have a number in A1 638.75 (called a TRANSOM) and another number in A3 573 (called LINK)

A1: 638.75 (TRANSOM)
A3: 573 (LINK)

Between those two numbers there must ABSOLUTELY be a minimum distance of 14.

Example: 638.75-573=65.75

But if it were say: 13, then A1 would be adjusted automatically by 1 make sure there is a distance of 14 at all times and A3 can never ever change.

Example: 560 (A1)-573 (A3)=13 (< really wrong and bad)
Example: 559 (A1)-573 (A3)=14 (< YaY, minimum achieved

A1: Flexible
A3: Can never change
Requirement: Minimum 14 between A1 and A3 (with only A1 changing)

How can I do this? I am at a complete loss.

Please help?

Thank you all for your help and time,
- TwoCoffeeSnobs

No formula at all.

Just me adding two numbers to A1 and A3.

Only VBA? I am not that good with it and still learning.

Option three would work, then I can show what it "was" meant to be and what it "has" to be.

How would I go about this?