This can be done using scripts. I've searched and found the following which I haven't tested, but should work.
You should've posted this in the Scripts & Pop-ups forum,

Code:
 ;Courtesy Yoinx on Hawkee
alias setchans { 
  set %relay.chan1 #channel1 
  set %relay.chan2 #channel2 
} 
on *:text:*:%relay.chan1: { 
  if ( $chan(#).cid == 1 ) { 
    scid 2 msg %relay.chan2 $timestamp  $($+(<,$nick,>)) $1- 
  } 
  if ( $chan(#).cid == 2 ) { 
    scid 1 msg %relay.chan2 $timestamp  $($+(<,$nick,>)) $1- 
  } 
} 
on *:text:*:%relay.chan2: { 
  if ( $chan(#).cid == 1 ) { 
    scid 2 msg %relay.chan1 $timestamp  $($+(<,$nick,>)) $1- 
  } 
  if ( $chan(#).cid == 2 ) { 
    scid 1 msg %relay.chan1 $timestamp  $($+(<,$nick,>)) $1- 
  } 
} 

on *:action:*:%relay.chan1: { 
  if ( $chan(#).cid == 1 ) { 
    scid 2 msg %relay.chan2 $timestamp  $nick $1- 
  } 
  if ( $chan(#).cid == 2 ) { 
    scid 1 msg %relay.chan2 $timestamp  $nick $1- 
  } 
} 
on *:action:*:%relay.chan2: { 
  if ( $chan(#).cid == 1 ) { 
    scid 2 msg %relay.chan1 $timestamp  $nick $1- 
  } 
  if ( $chan(#).cid == 2 ) { 
    scid 1 msg %relay.chan1 $timestamp  $nick $1- 
  } 
} 
on *:join:%relay.chan1: { 
  if ( $chan(#).cid == 1 ) { 
    scid 2 msg %relay.chan2 Joins: $nick $address($nick,5) 
  } 
  if ( $chan(#).cid == 2 ) { 
    scid 1 msg %relay.chan2 Joins: $nick $address($nick,5) 
  } 
} 
on *:join:%relay.chan2: { 
  if ( $chan(#).cid == 1 ) { 
    scid 2 msg %relay.chan1 Joins: $nick $address($nick,5) 
  } 
  if ( $chan(#).cid == 2 ) { 
    scid 1 msg %relay.chan1 Joins: $nick $address($nick,5) 
  } 
} 
on *:part:%relay.chan1: { 
  if ( $chan(#).cid == 1 ) { 
    scid 2 msg %relay.chan2 Parts: $nick $address($nick,5) 
  } 
  if ( $chan(#).cid == 2 ) { 
    scid 1 msg %relay.chan2 Parts: $nick $address($nick,5) 
  } 
} 
on *:part:%relay.chan2: { 
  if ( $chan(#).cid == 1 ) { 
    scid 2 msg %relay.chan1 Parts: $nick $address($nick,5) 
  } 
  if ( $chan(#).cid == 2 ) { 
    scid 1 msg %relay.chan1 Parts: $nick $address($nick,5) 
  } 
} 

on @*:mode:%relay.chan1: { 
  if ( $chan(#).cid == 1 ) { 
    scid 2 mode %relay.chan2 $1- 
  } 
  if ( $chan(#).cid == 2 ) { 
    scid 1 mode %relay.chan2 $1- 
  } 
} 
on @*:Mode:%relay.chan2: { 
  if ( $chan(#).cid == 1 ) { 
    scid 2 mode %relay.chan1 $1- 
  } 
  if ( $chan(#).cid == 2 ) { 
    scid 1 mode %relay.chan1 $1- 
  } 
} 
on @*:topic:%relay.chan1: { 
  if ( $chan(#).cid == 1 ) { 
    scid 2 topic %relay.chan2 $1- 
  } 
  if ( $chan(#).cid == 2 ) { 
    scid 1 topic %relay.chan2 $1- 
  } 
} 
on @*:topic:%relay.chan2: { 
  if ( $chan(#).cid == 1 ) { 
    scid 2 topic %relay.chan1 $1- 
  } 
  if ( $chan(#).cid == 2 ) { 
    scid 1 topic %relay.chan1 $1- 
  } 
} 
;courtesy Snooop on Hawkee
on *:kick:%relay.chan1: { 
  if ( $chan(#).cid == 1 ) { 
    scid 2 msg %relay.chan2 7<14AwesomeChat|#Chat7>  $knick $address($knick,5) Has Been Kicked Out. 
  } 
  if ( $chan(#).cid == 2 ) { 
    scid 1 msg %relay.chan2 7<14Topirc|#Cafe7> $knick $address($knick,5) Has Been Kicked Out. 
  } 
} 

on *:kick:%relay.chan2: { 
  if ( $chan(#).cid == 1 ) { 
    scid 2 msg %relay.chan1 7<14AwesomeChat|#Chat7>  Has Been Kicked Out 
  } 
  if ( $chan(#).cid == 2 ) { 
    scid 1 msg %relay.chan1 7<14Topirc|#Cafe7> $knick $address($knick,5) Has Been Kicked Out 
  } 
}


The two scripters that actually wrote those codes have been referenced in remarked (;) statements