This process was sometimes called linkage editing and the output known as a load module. A compiler works with what are sometimes called 3GL and higher-level languages. An assembler works on programs written using a processor's assembler language.
In general, however, when between vowels (as in exactamente) the Spanish x is pronounced like the English ks sound but softer or less explosive. When it comes before another consonant (as in expediciÃ³n), it has the s sound in some regions/countries but the soft ks sound in others.
The combination ll in Spanish words is traditionally treated as a single letter and is pronounced as consonant \y\ in American Spanish. When such words enter English, sometimes that sound persists. At other times it is pronounced just like ll would be in an English word: that is, as \l\.