Bug 122254 Not Like operator is missing in the Filter tab of Data Set window
data/org.eclipse.birt.data/src/org/eclipse/birt/data/engine/script/ScriptEvalUtil.java
final String reservedChars = "([{^$|)?*+.";
		int patternLen = patternStr.length();
		StringBuffer buffer = new StringBuffer( patternLen * 2 );
		
		for ( int i = 0; i < patternLen; i++)
		{
			char c = patternStr.charAt(i);
			if ( c == '\\' )
			{
				 
				
				++i;
				if ( i < patternLen )
				{
					c = patternStr.charAt( i );
					if ( c == '%' || c == '_' )
						buffer.append( c );
					else if ( c == '\\' )
						buffer.append( "\\\\");		
				}
				else
				{
					buffer.append( "\\\\" );  	
				}