recording two instruments at once... ...

Hi everyone,

I recently received an informative response to the below question, but I must be doing something wrong, because as of yet I've been unsuccessful. Any further help would be much appreciated:

ORIGINAL QUESTION:
"I need to record my bassist and guitarist simultaneously onto separate tracks in Cool Edit Pro. I'm using an old Peavey (1980's) mixing board with twelve XLR inputs. I have the amplifiers mic'ed and going to separate XLR inputs on the mixing board. I'm then going RCA (one red and one white) from the mixing board's "Tape Out" to an 1/8" input in back of computer."

ORIGINAL ANSWER:
"Pan 1 signal hard left, the other hard right. Make 2 mono tracks in Cool Edit Pro, tell one track to listen to input L, and the other track to listen to input R. Arm them both for recording, press record, and play."

FIRST, A FEW KEY QUESTIONS:
How, in step-by-step detail in Cool Edit Pro, do I "tell one track to listen to input Left" and the other to "listen to input Right"?

Another question: if the signal is being "fed" through one 1/8' male adapter, then how does the computer "know" that more than one separate signal (i.e., the "left" and the "right") is coming from the Peavey mixing board?

HOW I'VE TRIED AND FAILED:
"I've tried many different things, such as: opening the "Recording Devices" dialog box for each track, then choosing left channel for
one track, and right channel for the other track. This action converts each track to mono. Then, I enable the two tracks to record simultaneously, I hit record, and then only one instrument is recorded - but twice - onto each mono track."

YOUR FURTHER ADVICE (fill in the blank............please!!)

Many thanks in advance!