recursive list of all files in a directory

recursive list of all files in a directory
How can I get a recursive list of files from a certain directory and later loop over all files in this list?
In "pseudo-code", what I want is something like this:
(in red, the stuff I donÂ´t know how to do)

ListFileNamesInDir $Directory $fileNames
startLoop:
${LineFind} "$file" "$file" "1:-1" "DoSomething"

next $file from $fileNames

StrCmp $file "" startLoopDone startLoop
startLoopDone: