it would be easy to code it but the issue is what type of number system your dealing with. See in assembly rol,ror rely on the state of the processor carry flag depending on what processor your coding with. 6809 is exactly like that. 68000 however does not use the carry and requires roxL roxr to do it properly if i recall. Maybe your thinking of LSL and LSR? These two commands could very easily be programmed in basic as they are simple bit shifts introducing 0's on the ends depending which way your rotating your data. ROL & ROR are kinda useless with basics numbering system.
edit: LSL & LSR
essentially all we are doing here is a division in half or a multiply by 2 for each shift....easy to code in basic.
0100 000 LSR-> 0010 000 64 now equals 32
0100 000 LSL<- 1000 000 64 now equals 128