assembly - How to use IMUL and MUL instruction in emu8086?

Question

How to use IMUL and MUL in emu8086? .. movzx in emu8086 is not allowed

like for example movzx is not allowed in emu8086, this alternative would allow me to use the instruction, does emu8086 has something like this alternative so i use instructions IMUL / MUL?

1  movzx bx,centerBot ;not allowed in emu8086
2
3  mov bh,00          ;alternative of line 1 
4  mov bl,centerBot   ;to move centerBot to bx
                      ;in emu8086

is there something like this with the IMUL/MUL in emu8086 so i can these instructions?