Querystring parameter does not appropriate syntax



I want to capture the value querystring in one of the URL but it seems the Querystring in the parameter does not  expect the value  due to inappropriate syntax


example : abc.com/?abc_xyz-op= true.  I want to capture this when the value is true. It would be really straightforward if the querystring did not have "-" in it. I could have just create  querystring variable and than attach to the custom dimension in GA tag.

Is there a solution which can resolve it. If its not in scope of tealium variable,I guess I need to create a javascript variable and map it  accordingly. is there a shorter way to this?