Linear Reg Value input problem

[ianwaugh@xxxxxxxxx (Ian Waugh)]

Hi All,
       I'd like to calculate the LinearRegValue, changing the value of 
Length on a bar by bar basis. The code would be something like:

Len=0;
Len=Len+1;
plot1(LinearRegValue(close,Len,TargetB);
etc...

However, you cannot alter the value of Len for LinearRegValue on a bar 
by bar basis.

Any ideas how I can do this?

Cheers,
Ian