Not to a 70d newb. I don't know what pan is in a recorder. So, I wouldn't know why I would use it or how to.
In general, the Pan feature assigns individual channels to either left, right, or somewhere in between.
According to what Volt posted, unless you're mixing your inputs for a real-time output using the 2Mix feature, any Pan setting will be ignored by the unit. If you DO want to mix using 2Mix, Left 12 is full left with no right channel output, and Right 12 is full right, with no left channel output.
As Volt suggests, when recording direct to tracks (NOT using the 2Mix feature) Input channels 1&3 will automatically be assigned to pure left, and channels 2&4 will be assigned pure right.
Does this make sense?