How to return a word in expression?

[cjphoto]

Hey there. I need a little help with an expression. I'm creating an expression that turns a name, such as Johnson, Chris into RV - C. Johnson. So far, I've created the expression below which returns RV - C. Johnson, , Chris. I can't figure out how to return the last name properly. Any ideas?

ISNOTBLANK([NAME]),
"RV - " &
RIGHT(INITIALS([NAME]), 1) & ". " &
SPLIT([NAME], " ")

[Suvrutt_Gurjar · Accepted solution]

I think you have almost got it correct. Please try 

CONCATENATE("RV - ", RIGHT(INITIALS([Name]),1),". ", INDEX(SPLIT([Name],","),1))

[cjphoto]

Yes! This is exactly what I was looking for. Now I see where INDEX needed to go. Thank you very much!