how can i count so meny chr and then redo string

i have a string of lets say

webString = " '!WHOLESALE!; % 0f; % anonymous; % c\*h\*e\*a\*p\*e\*r; % cheaper; % fixed; % free; % improv; % legal; % or more; % proven; % rate; % risk free; %off for all New Software; %OFF of; %off retail; %RND_AD; %VIA' Took 1 Seconds  "

how can i make it only lets say 25 chr long and then it chops it and adds "....."

how do i do this via code

thanks
Johnny
aka Pern