Configuring Multiple ADC channels (12 ADC Channels) in Sequence Mode.

I'm using RL78/F13 R5F10BGF.

We have requirement of Reading ADC Data from 12 ADC Channels at every 10ms (No Interrupt). Initially we thought to configure the 12 ADC Channels in "sequential conversion with SCAN Mode" But we found in SCAN Mode we can configure only Maximum 4-ADC Channels and also in F13 there is only one conversion result register (ADCR) available. 

Can anyone guide me how can i achieve "sequential conversion with SCAN Mode" like Functionality For 12-ADC Channels. Also we don't want to generate interrupt after every conversion completion.