>This is part of script. I want to only run the code if the @Filename contains the string ".doc" but I'm getting an error on the syntax.
>
>

>Msg 102, Level 15, State 1, Line 133
>Incorrect syntax near '@Filename'.
>
>			IF  CONTAINS(@Filename, '.doc')
>				Set @CONVERTSCRIPT = 'c:\Tiff\RTFConverter.exe "' + @DocumentID + '|c:\ImpactMD\Export\' + @DocumentID + '.rtf"'
>				Print 'Convert Script - ' + @CONVERTSCRIPT
>				exec master.dbo.xp_cmdshell @CONVERTSCRIPT, no_output
>

Try with:

IF CHARINEX('.doc', @Filename) > -
    ..

From BOL:
Is a predicate used to search columns containing character-based...