In the Torchmate driver software, select SET UP/OUTPUT LINES.  The window above will open.  In the beginning with M Codes 50 and 51, change the last two columns so they appear as shown above.   In this illustration, an incremental dwell time of  2 seconds has been set for pre-heat before the cutting oxygen comes on.  We will be placing several back-to-back M51 commands at the beginning of each shape to be cut.  Together they will add up to the total dwell time for pre-heating.  If we set the dwell for pre-heat here at a full 8 or 10 seconds, the torch would dwell for that same period after completing the cut, blemishing the material.
 
A dwell of 3 seconds has been set for the torch to penetrate the material before starting to move.  Now click on OK and exit the window.

Next, with your G-code file loaded, select FILE/EDITOR.  The  G-code will appear in a window, as shown below.

At the beginning of each shape to be cut is a G00 (rapid traverse with torch off) line.   At the end of each such line of code, add a space, and then "M51".  This will provide two seconds of pre-heat dwell.
 
Insert additional lines of code repeating the M51 command to get the total pre-heat time desired.  Here, a total of 10 seconds (5 times 2 seconds) has been set.  Then click on exit, and respond yes when asked if you want to change the G-code file.
 
Your machine will now dwell 10 seconds for pre-heat, and again for 3 seconds after the cutting oxygen comes on before the torch starts to move.
 
Place this same sequence of lines at the beginning of each shape to be cut.  You can either do it in the Torchmate G-code editor, or in a standard text editor with a "find" feature that will locate each occurrence of G00 in your file.   Number the inserted lines of code sequentially, as shown here.