Is there a term for words that are spelled the same in a foreign language?

The closest I believe is "cognate" (from Merriam-Webster Online ):
3
a: related by descent from the same ancestral language
b: of a word or morpheme : related by derivation, borrowing, or descent

However, translators must beware of cognates, because the meaning and usage often varies in subtle ways between languages. For instance, "mist" in German" is what farmers put on the field at night, causing a steam (ie a 'mist') to appear above the field the next morning that obscures sight.

http://en.wikipedia.org/wiki/List_of_French_words_and_phrases_used_by_English_speakers

In the above wikipedia article are a list of French words which have retained their original meaning and spelling. As far as I could tell, a single word or expression meaning unmodified foreign words (my definition) which have been adopted into the English language, does not exist.

(Emphasis mine)

This article, however, covers words and phrases that generally entered the lexicon later, [...] As such, they have not lost their character as Gallicisms, or words that seem unmistakably foreign and "French" to an English speaker. The phrases are given as used in English, and may seem correct modern French to English speakers, but may not be recognized as such by French speakers as many of them are now defunct or have drifted in meaning. A general rule is that, if the word or phrase retains French diacritics or is usually printed in italics, it has retained its French identity.

A similar list exists for Italian words and phrases, again these words retain their "ethnical" spelling and meaning however, their pronunciation may differ from that of Italian.

On a side note, Loanwords or its equivalent expression lexical borrowing, expresses the concept of foreign words which were adopted and manipulated in the past and today appear and sound native-like. For example the English adjective, handy, was loaned to the German language but means mobile phone consequently "Handy" is a German noun.

EDIT:

In The Cambridge Encyclopedia of Language, (Edition 2010) David Crystal. The author states on p302

When languages have been shown to have a common ancestor, they are said to be cognate.

The clearest cases are those where the parent language is known to exist. For example, on the basis of the various words for 'father' in the Romance languages, it is possible to see how they all derived from the Latin word pater.

Examples:

Italian padre; Spanish padre; French père; Portuguese pai; Catalan pare.

on p340, Crystal talks about language changes; sound, grammatical, and semantic. Under the heading of New words and old he makes the following remarks:

In most languages the vast majority of new words are in fact borrowings from other languages [...] Borrowing proceeds in all directions, Weekend and parking have been borrowed by French from English; chic and savoir-faire have been borrowed by English from French. Some languages have borrowed so extensively that native words are in a minority

In nowhere (could I find) does the esteemed author, David Crystal, mention a linguistic word, phrase or term which means native and foreign words having the same meaning and spelling.

"Homograph" (almost, sorta) means what you want - two words that are spelled the same. As a comment points out, you should be careful of words that look the same but have different meanings - what another comment calls "false friends". "Homograph" does not specifically denote words from different languages, although that may be a finer distinction than you're inclined to make.

Related (but not what you are seeking): "Homonym" is a more commonly used word which, I think, also indicates that the words are pronounced the same. To round it out, "Homophone" would be 'sound-alike'.

More detail in the question would be nice, but I think (from a comment) might also end with "this is a discussion for Programmers.SE or its chat room".