string - How to combine sql text field with extra text and handle php as if it were one sql text field? -

for joomla 3.1 website i'm building need little help.

basically trying automate inclusion of pluginline in article default.

normally article have contain pluginline have article output plugin. example given:

content of article: <p>lorem ipsum.....</p> <p>{plugintag var1=val1|var2=val2|etc.}</p> 

and stored in database text field.

now in order have plugincontent included in every article requires user add pluginline manually every time new article added.

i want remove pluginline articlecontent , add @ view article php file. instead of output:

<div><?php echo $article->content; ?></div>  

in view article php file, want somehow add pluginline $article->content. tried replacing $article->content $new_content , created new value before it:

$new_content = $article->content . '<p>{plugintag var1=val1|var2=val2|etc.}</p>'; 

but outputs exact pluginline underneath content , isn't handled plugin, no pluginconent being shown.

what doing wrong. want $new_content being read if contains the article content including pluginline if 1 textfield actualy being build of sql text field , text it.