AB version of MetaStock formulas

["b519b" <b519b@xxxx>]

I need a bit of help converting the following 2 MetaStock formulas 
into AFL: 
MSF = MetaStock forumla, 
AFL = my attempt at proper AFL translation.

MSF: Mov(C,20,VOL) > Mov(C,20,S)
AFL: ???(C,20) > MA(C,20); // Is there a Volume adjusted Simple 
Moving Average in AFL? If not, how difficult would it be to write 
one?

MSF: ROC(Mov(C,20,S),1,$) > 0 
AFL: ROC(MA(C,20),1) > 0; // I think this is it, but I would like to 
know what the "$" signify in the MetaStock ROC function.

Thanks in advance.

b