Random Numbers

[DDon]

Below is a list of doors that Have a interlock function. Two doors cannot be open at the same time. Below is a small Section of doors That cannot be open at the same time. I have other lists of doors, that are smaller and larger than the list here. Is there some kind of VBA Code or function I can use so no two doors can be opened at the same time.

Thank you For your time
Don

Section 400 Q R
400
401
404
410
420
430
440
450
460
470
480
490

[patel]

it's not clear for me

[Excel Fox]

As patel indicated, the question is not clear, in other words, doesn't make sense. Can you please rephrase in a more easy-to-understand manner?

[DDon]

Below is a list of door numbers 827,828,G23 ect. All doors are in the same location. No two doors are allowed to be open at the same time. I need find all different combination that the list of doors numbers can possibly come together. This is just a small list.
Please help

Work Furlow
827 828
827 829
827 G23
828 827
828 829
828 G23
829 827
829 828
829 G23
G23 827
G23 828
G23 829