This show was a CBS special that aired on November 10, 1977. Here is a tv guide description:

Channels 11 and 13: The Winners 'Mobile Maidens'; A story of three young
girls in California and their plan to distribute surplus food to the poor.
Starring Kenia Borell, Nita Dee, Julie Piekarski and Laura Wallace

http://news.google.com/newspapers?id=Skk0AAAAIBAJ&sjid=X2cEAAAAIBAJ&pg=5923,2522365&dq=piekarski+mickey+mouse&hl=en

Here is an old newspaper article that give a larger description of the show:

'Winners Shows Three Who Care'

http://news.google.com/newspapers?id=tiQtAAAAIBAJ&sjid=sqQEAAAAIBAJ&pg=2078,604183&dq=the+winners+mobile-maidens&hl=en