Match Regular Expression Function input string format

Hi,

I am new to labview and was having some difficulties using the Match Regular Experssion Function.  

I am using labview to communicate with a sensor.  I have installed the NI device driver to do so.  The output of my sensor is in the format, 

X20

R40 P20 A123.  The numbers in this case are arbitrary.  I am trying to use Match Regular Expression Function to display and perform mathematical operations on the numbers.  I am having difficulties formatting the input string on the Match Regular Expression Function.  Could you please give me some tips on how to format the example I provided.  

Thank