Attribute syntax and search filters

I originally had a request from developers to allow substr searches on the "drawId" integer attribute you see below. As you know, substr searches on integers are not supported so I changed the schema and modified the attribute type to a numeric string. This worked as expected but now they are coming back to me asking why negative numbers are not being matched in their search filters. After some reading I understand the numeric string syntax is used to hold strings comprised of one or more ASCII numeric digits digits and/or space characters. The hyphen is not allowed, so it is not possible to represent negative values. Is there any alternative here? Original schema entry attributetype ( 3.0.0.3 NAME 'drawId' DESC 'ID of the retailer a user is assigned to' EQUALITY integerMatch SYNTAX 1.3.6.1.4.1.1466.115.121.1.27 SINGLE-VALUE ) Current schema entry. attributetype ( 3.0.0.3 NAME 'drawId' DESC 'ID of the retailer a user is assigned to' EQUALITY numericStringMatch SUBSTR numericStringSubstringsMatch SYNTAX 1.3.6.1.4.1.1466.115.121.1.36 SINGLE-VALUE )