Excel VBA - Combination - Complicated Problem

Hi,

I have a model, which can increase up to 20 characters. Right now, it is at 6. I have listed the replacement below. a can only be replaced with A. b can only be replaced with B and so forth and so on. I want to change depending on the variation chosen, from 2, 3, 4, or 5.


Model: a b c d e f
Replacement: A B C D E

2 Variation (10 combinations)
A B c d e
A b C d e
A b c D e
A b c d E
a B C d e
a B c D e
a B c d E
a b C D e
a b C d E
a b c D E

3 Variation (6 Combinations)
A B C d e
A b C D e
A b c D E
a B C D e
a B c D E
a b C D E

4 Variation (3 Combinations)
A B C D e
A b C D E
a B C D E

Wow, thank you so much! You're the best!