Added in 1.9.0

/sline [-ar] <#channel> <N|nick>

Selects or de-selects lines in a channel nickname listbox. It can select either the Nth nickname in a listbox, or a specified nickname.

Switches

-a - Appends selection to current selection.
-r - Deselects instead of selects.

Parameters

<#channel> - Channel where the listbox is located.
<N|nick> - Nick or the N'th nick to select.