Trying to extract data after several non-data lines

[Jason Hsu, Linux user]

I'm trying to process data in a file.

The first part of the file consists of several lines that are irrelevant as far 
as the data processing goes.

The last line before the data begins reads 
"X_Value,Voltage_wrist,Voltage_midarm,Comment".

The data consists of three columns of comma-separated floating-point numbers.

I'm using the fgetl command to read the lines in the file.  But I can't figure 
out for the life of me how to get the algorithm to notice 
"X_Value,Voltage_wrist,Voltage_midarm,Comment" so it can start switching to a 
different mode.

Can someone shed some light on how to get the algorithm to notice that 
particular line?

-- 
Jason Hsu, Linux user <address@hidden>