Collating Information but exclude errors

So the end result I want is -

Cooperation, Curriculum Linked Activities, Familiarization, Fun, Personal Challenge, Personal Development, Personal State Management, PSE, Self Belief, Skill Acquisition, Support, Training Course

BUT...

It needs to be depandant on the #N/A's as it could change too -

Cooperation, Curriculum Linked Activities, Familiarization, Fun, Personal Challenge

I can get it so the end result is - Cooperation, Curriculum Linked Activities, Familiarization, Fun, Personal Challenge, Personal Development, Personal State Management, PSE, Self Belief, Skill Acquisition, Support, Training Course, , , , , , ,

But need to exclude these last commas.

Hope that makes sense

So sheet one is a matrix - that 1 Signifies it matches that point - Sheet 2 refers that to a Number to reflect the Lookup.

Sheet 4 is where having the issue - (I have proberly gone the long way round it all)

I have Sorted - I want to combine as mentioned above to give result such as -

Cooperation, Curriculum Linked Activities, Familiarization, Fun, Personal Challenge, Personal Development, Personal State Management, PSE, Self Belief, Skill Acquisition, Support, Training Course

Hope that abit more useful