you can convert a number into a character using the CHR$() function
format is strMyChar=Chr$(intMyNum)
check the ascii symbol table for details but upper case "A" is ASCII(65)
so assign 818 0 to be 818 A
strMyChar = chr$(intMyNum+65)
where intMyNum is the number you want to convert. note you will need to insert some range checking ie intMyNum in range 0 to 26, if more then devise some strategy to handle this.
Bear in my some ASCII characters are non printable (below 32 offhand)