Load byte value from a DB variable into 16-bit register (sign or zero extend a byte)

I m using MASM compilor and DOSBOX. I want to want to save value from a variable into register. I want to save num1 value into cx register. How can I do that?

      .MODEL SMALL
.STACK  50H
.DATA
num1 db '5'
    NL  DB  0DH, 0AH, '$'        
    msg     db ?,0AH,0DH,"Enter an odd number between 0 to 10:$"
     nxtline db 0Ah,0DH,"$"
.CODE
MAIN PROC
    MOV AX, @DATA
    MOV DS, AX
    
    
            
              LEA DX,msg     
              mov ah,9
              int 21H
              LEA DX,nxtline    
              mov ah,9
              int 21H
              
              MOV AH,1                    
              INT 21H 
              LEA DX,nxtline    
              mov ah,9
              int 21H
              
              
              
       mov bl,al   ;save the value from input
              mov num1,bl
               LEA DX,num1     
              mov ah,9
              int 21H
              mov cl,al 
              
   main endp
   end main

You are losing the value entered by the user in AL. You input one char with this:

          MOV AH,1                    
          INT 21H 

The char is stored in AL, but before you save the value in BL you display a line break:

          LEA DX,nxtline    
          mov ah,9
          int 21H

And the value in AL is gone because this interrupt uses AL to display a string. The solution is to save the value in BL before you display the line break:

          MOV AH,1                    
          INT 21H 
   mov bl,al   ;save the value from input
          LEA DX,nxtline    
          mov ah,9
          int 21H

Edit : move value into CX :

xor cx,cx       ;CLEAR CX.
mov cl,bl       ;MOVE CHAR INTO CL.
sub cl, 48      ;CONVERT CHAR TO DIGIT, EXAMPLE: '5' -> 5.