Making third Validation list that is dependent in column A&B (with illegal characters)

[Elainefish]

am going to make a third list (column C) which is dependent on Column A&B
it was suggested that I use =INDIRECT(SUBSTITUTE(A5&B5," ",""))
but it does not work because I am using invalid characters
I am not sure how to insert the Vlookup formula in =INDIRECT(SUBSTITUTE(B2&C2," ","")) formula

I have tried this: =INDIRECT(SUBSTITUTE(A5&vlookup(B5,NameLookup,2,false)," ",""))
but it seems that something is wrong


Really appreciate your help