Just loop through all the child entities, and search for the name your after. It shouldn't matter they all have the same name.
;
parent = parent_entity
c = countchildren()
for loop = 1 to c
entity = getchild(parent_entity,c)
if entityname(entity) = "name you want" then
; this entity matches
end if
next
NOT real code, but gives you the idea :o)
;
parent = parent_entity
c = countchildren()
for loop = 1 to c
entity = getchild(parent_entity,c)
if entityname(entity) = "name you want" then
; this entity matches
end if
next
NOT real code, but gives you the idea :o)