optional conversion routine in transfer rules not avail. for units

Hi,

I'm trying to load unit fields in <b>external format </b> to the InfoObject CUNIT.

In some cases the SID entries in the internal format do not correspond

to the german external representation. This is the reason why

I need the optional conversion option checked in the transfer rules.

Unfortunately this check box is deactivated.

How can I make this button available or how can I make a conversion

routine available for the unit InfoObjects??

thanks for your help.

regards, te