Yhyjyk

I can get the following code to compile, using luatex, with the Hindi/Devanagari characters correctly printed in the pdf:

documentclassarticle
usepackagefontspec
setmainfontTimes New Roman
newfontscriptDevanagarideva,dev2
newfontfacehindi[Script=Devanagari]Lohit-Devanagari.ttf

begindocument
Here is normal text.
hindi नमस्ते 
enddocument 

However, I'm using a program that outputs the tex and that won't allow me to type the Hindi script into my tex editor; instead, it will only give me the unicode version of the word, "नमस्ते", which is "<U+0928><U+092E><U+0938><U+094D><U+0924><U+0947>".

How can I get luatex to compile correctly from these raw code characters? What I want to compile (to produce a pdf with the single word "नमस्ते") is something like this:

documentclassarticle
usepackagefontspec
setmainfontTimes New Roman
newfontscriptDevanagarideva,dev2
newfontfacehindi[Script=Devanagari]Lohit-Devanagari.ttf

begindocument
Here is normal text.
hindi <U+0928><U+092E><U+0938><U+094D><U+0924><U+0947> 
enddocument 

...but that won't work.

(added an extra operation in the Lua function 'conv' to address the OP's follow-up request)

Since you're using LuaLaTeX, here's a solution that employs a Lua function to convert strings of the form '<U%+(.-)>' to '\char"%1'; here, %+ represents the literal character + and %1 represents the non-greedy "capture" of the pattern (.-) -- in words: "0 or more characters other than >". In a second step, the Lua function converts any whitespace characters present in the string to explicit (interword) whitespace.

In addition, the code also sets up a LaTeX macro that acts as a front-end for the Lua function. Thus, one may call the Lua function via a conv<your string here> directive.

You can either manually encase the sequences of unicode code in conv... statements or, depending on how far you can get your program to do the work for you, instruct the scripting program to encase the sequences of unicode code in a conv... statements automatically.

documentclassarticle
usepackagefontspec
setmainfontTimes New Roman
newfontscriptDevanagarideva,dev2
newfontfacehindi[Script=Devanagari]Lohit-Devanagari.ttf

%%%% -- copy the next eight lines of code to your document -- 
usepackageluacode % for 'luacode' env. and 'luastringN' macro
beginluacode

function conv ( s ) 
 s = s:gsub ( '<U%+(.-)>' , '\char"%1' ) 
 tex.sprint ( ( s:gsub( '%s+' , '\ ' ) ) )
end

endluacode
newcommandconv[1]directluaconv(luastringN#1)

begindocument
Latin-alphabet text.

hindi नमस्ते 

hindi conv<U+0928><U+092E><U+0938><U+094D><U+0924><U+0947> 

hindi conv<U+0928><U+092E><U+0938><U+094D><U+0924><U+0947> <U+0930><U+093E><U+091C>
enddocument