offset spline?

I have a plate that I would like to cut to a body panel profile. I created a spline following the outline of the panel in the assembly and then brought the sketch into the part. Now I would like to offest the spline by .625" and SolidWorks will not allow me to offset it.

Is there a work around other than manually attempting to draw a new spline?

Thank you

SolidworksParts And Features