Message is probably caused by using other than Tiny memory model, in which static storage variables are placed at address >= 0x100, and as a result MOV can't be used.
Error message is misleading. I tried to compile the same snippet in CW 6.3. It produced
Error : C18700: Unknown Opcode Operand Combination: Opc.:MOV/Dest.:Ext/Source:Imm8.
, which makes sense.
To place variables in zero page use DATA_SEG pragma like this:
#pragma DATA_SEG __SHORT_SEG MY_ZEROPAGE
int delaycomm;
#pragma DATA_SEG DEFAULT // restore memory model default placement