Hi Bertto and welcome to the board
To the best of my knowledge, this is simply an HTML question. You do something like this:
<object width="550" height="400">
<param name="movie" value="somefilename.swf">
<embed src="somefilename.swf" width="550" height="400">
</embed>
</object>
The double tagging (embed AND object) is to cover browser glitches.
If you want to make Flash content using PHP, you can! Try this page of the manual.
Best o luck
Norm