First, don't title your threads with generic text that does not hint at all as to the content of the thread. "Quick Question" could be about anything in the universe, at least put a keyword in there that can be picked up by a search should someone have the same problem in the future.
Second, the question requires more information because there are at least two scenarios that are possible:
A) you are in 2D render mode, which preserves text without erasing the screen each loop
B) you are in 3D render mode, which clears the whole screen every sync
(if you have any 3D objects, you are in 3D mode as DBP automatically switches, if you have no 3D objects, DBP remains in 2D mode until a 3D object is present)
If your scenario is 'A', then you should put your text on the screen before the loop. If your scenario is 'B', you can't avoid putting text on the screen every sync unless you don't want to see it.
As for excluding commands in a loop, you would use conditional statements such as IF...ENDIF or IF...THEN.
example:
REM Place at the end your loop
IF SHIFTKEY() THEN TEXT 10,10,"Hello World"
You might even be using PRINT, which is not a great idea, you should be using TEXT.
_____________________
Windows Vista: Just say no.