[R] data file import - numbers and letters in a matrix(!)

[Felix Wave]

Hello,
I have a problem with the import of a date file. I seems verry tricky.
I have a text file (end of the mail). Every file has a different number of measurments 
witch start with "START OF HEIGHT DATA" and ende with "END OF HEIGHT DATA".

I imported the file in a matrix but the letters before the numbers are my problem 
(S= ,S=,x=,y=).
Because through the letters and the space after "S=" I got a different number
of columns in my matrix and with letters in my matrix I can't count.


My question. Is it possible to import the file to got 3 columns only with numbers and 
no letters like x=, y=?

Thank's a lot
Felix




My R Code:
----------

# na.strings = "S="

Measure1 <- matrix(scan("data.dat", n= 5063 * 4, skip =   20, what = character() ), 5063, 3, byrow = TRUE)
Measure2 <- matrix(scan("data.dat", n= 5063 * 4, skip = 5220, what = character() ), 5063, 3, byrow = TRUE)



My data file:
-----------

FILEDATE:02.02.2007
...

START OF HEIGHT DATA
S= 0 y=0.0 x=0.00000000
S= 0 y=0.1 x=0.00055643
...
S= 9 y=4.9 x=1.67278117
S= 9 y=5.0 x=1.74873257
S=10 y=0.0 x=0.00000000
S=10 y=0.1 x=0.00075557
...
S=99 y=5.3 x=1.94719490
END OF HEIGHT DATA
...

START OF HEIGHT DATA
S= 0 y=0.0 x=0.00000000
S= 0 y=0.1 x=0.00055643



The imported matrix: 
>
      [,1]           [,2]           [,3]           [,4]          
 [6,] "S="           "9"            "y=4.9"        "x=1.67278117"
 [7,] "S="           "9"            "y=5.0"        "x=1.74873257"
 [8,] "S=10"         "y=0.0"        "x=0.00000000" "S=10"        
 [9,] "y=0.1"        "x=0.00075557" "S=10"         "y=0.2"       
[10,] "x=0.00277444" "S=10"         "y=0.3"        "x=0.00605958"