I don't believe it's possible to write text on top of animations with the built in text commands... The first thing that springs to mind would be to use sprites:
rem paste text on top of animation
SpriteNum=TextSprite("Hello World")
sprite SpriteNum,20,20,SpriteNum
rem function for creating sprite with text on it
function TextSprite(string$)
rem local variables
local t as word
rem search for non existing sprite and image
for t=1 to 65535
if sprite exist(t)=0 and image exist(t)=0 then exit
next t
rem create image and paste text on it
create bitmap 1,text width(string$),text height(string$)
text 0,0,string$
get image t,0,0,text width(string$),text height(string$)
delete bitmap 1
endfunction t
TheComet