Package acronym: Other label for Acronym

i made a list of acronyms (Package acronym):

begin{acronym} 
    acro{SAP JCo}{SAP Java Connector}
    acro{RBG}{Regalbediengerät}
    acro{RBG-GEN}{Regalbediengerätes}
end{acronym}

I used a workaround for a german grammer thing. But now it Says in the text

……. Regalbediengerätes (RBG-GEN)……

I want:
……….. Regalbediengerätes (RBG) ……

Is there a way to change the label in text from RBG-GEN to RBG but keep RBG-GEN in acronymsß

Hope my Question got clear….