Convert numbers to symbols without string or char literals
C, 90 bytes

The line between a character and an integer literal is a very fine one in C.

a[]={8,0,31,2,3,4,61,5,9,7};main(d){for(;~(d=getchar());)putchar(d&gt;47&amp;d&lt;58?a[d-48]+33:d);}