Retrieving a word with numbers from another script?

There are a couple strategies you can use:

1. Iterate over all the children in the workspace and use pattern matching, as F4ULT1NTH3D4T4 suggests (I don't recommend this; why iterate over it manually if you don't have to?).
2. Merge it into a single script (so that the same script handles renaming the object). I recommend this method.
3. Use an ObjectValue, BindableFunction, or ModuleScript to transmit a reference to the object from one script to the other. (The script doing the renaming might add the Part to a list stored in the ModuleScript, for instance, or else it might add an ObjectValue to, say, workspace.RenamedParts (some folder that the main script knows about).)

You could have a ModuleScript whose sole purpose is to return a table that other scripts can share:

--Module script (let's call it "List" and put it in ServerScriptService)
return {}

--Script that does renaming
script.Parent.Name = "Hello".. math.random(1,100)
local list = require(game.ServerScriptService.List)
table.insert(list, script.Parent)

--Script that wants the list of items:
local list = require(game.ServerScriptService.List)
--do whatever you want to 'list'. Note that you cannot say "list = {}", but you can manually delete all the entries, if needed. ex:
local obj
for i = 1, #list do
    obj = list[i]
    --deal with obj here
    list[i] = nil -- remove the object from the list so we don't deal with it ever again in the future. We mustn't use table.remove or else that'll mess up the rest of the for loop.
end

http://wiki.roblox.com/index.php?title=Global_namespace/String_manipulation#Patterns

Number = ("Brick" .. count):match("%d+") --returns the count