Great, I'm glad that you understand the code I posted up above. The program you wrote is good, but I can show you something that will make the code a little shorter.
Take a look at this:
rem Screen Setup
Hide Mouse
rem Count Down
Text 0,0,"10" : Wait 400
Text 30,20,"9" : wait 400
Text 60,40,"8" : wait 400
Text 90,60,"7" : Wait 400
Text 120,80,"6" : Wait 400
Text 150,100,"5" : Wait 400
Text 180,120,"4" : Wait 400
Text 210,140,"3" : Wait 400
Text 240,160,"2" : Wait 400
Text 270,180,"1" : Wait 400
rem Blast Off
Load Sound "explode3.wav",1 : Loop Sound 1
Text 320,240,"BLAST OFF!!!" : Wait 800
I simply used the "Text" command instead of the "Print" command. The "Text" command is similar to the "Print", but the the "Text" command includes the coordinates, so the "Set Cursor" command is not needed.
Also, I used a colon to seperate some commands and keep them on the same line. Colons are to use because it keeps the length of your code down a lot, so you don't have to keep scrolling down. However, if you keep using the colon on the same line, eventually your going to have to scroll horizontally. If want some good examples of the colon being used take a look in the "20 line Challenge" fourm on this site.
Another way to write some code that will do a countdown is this:
rem Screen Setup
Hide Mouse
rem Countdown
For Num= 10 To 1 Step -1
Center Text 320,240,Str$(Num) : Wait 400 : Cls
Next Num
Load Sound "explode3.wav",1 : Loop Sound 1
Center Text 320,240,"BLAST OFF!!!" : Wait 800 : Cls
Center Text 320,240,"Press Any Key..." : Suspend For Key
This time I made the code a little better by using some more simple commands. The "Center Text" command is similar to the "Text" command, but the "Center Text" command just centers the text on the specified coordinates and the "Text" commands doesn't.
I also used the "Str$" command this time. The "Str$" command simply takes a number value and turns it into a string value. This was needed because the "Num" value was a interger value. The "text" command and the "Center Text" command only output string values, so the Num integer value needed to be turned into a string value.
Another command I used was the "Cls" command, which you probably already know, but anyways it simple clears the screen.
The next new command I used was the "For" "Next" loop. A loop is exactly that, it just keeps loop the code inside the loop. The "Step" command tells the "For" "Next" loop to go up or down by a certain value, in this case -1.
The "Suspend For Key" command just waits until the user press a key before executing the rest of the code.