that indicator doesn't come with TS.  it was sent to me by a friend.  Maybe we can find it on the web via a google search

It is not provided by default.here it is the indicator for tradestation :

inputs:
Price( Close ),
Length( 20 ),
UpLineColor( Green ),
DnLIneColor( Red ) ;

variables:
LRS( 0 ) ;

if LRS > 0 then
begin
SetPlotcolor(1, Uplinecolor);
end
else
begin
SetPlotcolor(1, DnLineColor);
end ;

LRS=LinearRegSlope( Price, Length );
Plot1( LRS, "LRS") ;