Replace character

Hi
I can replace a character with an un-related character from the symbol font
set as :
/=/ \rightarrow
wich will replace all occurances of '=' with the rightarrow character from
the symbol font set
Can I use the same concept to replace the '=' character with another
character from another font set (like a line drawing font set) and not just
be confined to the characters of the symbol set?

Thanks in advance