In a way you are making this harder than it needs to be.
You don't need to convert from ASCII to decimal, because ASCII is decimal.

All you need to do is write/store the ASCII strings into EEPROM. Then read them back via a subroutine that includes the LCDOut command. You may want to terminate your stored strings with a 0 (decimal 0 not ASCII) to indicate end of string, this allows each string to be different lengths.