You just start the image burning wizard, and point it to the .cue file- that's all.
If Alcohol complains about invalid imagefile, you have to edit the .cue file by with a text editor and remove any existing PATH from the image definition, e.g:
FILE "C:/Documents and Settings/superuser/My Documents/Trane03.wav" WAVE
should be changed to just
FILE "Trane03.wav" WAVE (.cue and bin must be in the same directory).
Mind you that Alcohol 120% can not burn any other .cue based image (just cue/bin), and it also cannot burn cue/bin images of multisession CD's (which are rather rare).