Could you please post a script where you need such identifier, or explain it a bit better?

alias con {
if (( $isid ) && ( $scid($1) )) {
var %i = 1, %j = $scon(0)
while ( %i <= %j ) {
if ( $scon(%i) == $1 ) {
return %i
}
}
}
}
This should give you connection number, when you give it Connection ID number, but I still can't think of any use for it...