1. Create a class (MyLookup) which inherits SysLookup and override the lookupDimension() method with the following code.
public static lookupDimension(FormStringControl _stringControl,
Name _dimensionName)
{
SysLookup::lookupDimension(_stringControl, _dimensionName);
}
2. Override the lookup method of the formcontrol.
public void lookup()
{
MyLookup::lookupDimension(this, 'CostCenter');
}