Find n-th occurrence of delimiter in string

[ssimop]

I need to locate the substring between the 7-th to eighth occurrence of a delimiter (namely semi-colon) in the following string.

str s="Description;A;100;;;Y;Help;;;400;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;"

Any advice is mostly welcome.

Let me add that I used tok but it misses any "empty" occurrence between to successive delimiters. I also tried findrx

findrx(subject pattern 0 4 a)

with cpMin, cpMax, but it fails in the case that the string contains unicode characters.

Many thanks in advance.