Do you have any separator like 116,101,115,116 because ascii starts from 0 and ends at 127 and can be extended. Or if your text jsut carries text the also conversion is possible else ambiguity may arise.
In general it's possible but without some further data/information like a delimiter between the numbers it could be quite difficult because the chars could have two or three digits and you would need multiple loops to approach the approximately string/value.
The below suggested mapsubstring-approach is surely a good starting-point but if your ASCII didn't contain just simple string-values else line-breaks, (multiple) spaces, tabs or other special chars you might not get the expected results. Therefore you should look for a delimiter and maybe there is already one not visible within the ASCII (a check with notepad++ would be useful) or this information exists within another field.
