Once you have read the text box into a string, you can use two different methods to parse it:
1. If you know exactly how many items to scan, you can use Scan function with the appropriate specifier for the terminator character (as in your example, "%s[xt44]" terminates scanning on a comma)
2. If you don't know how many items to scan, you can use strtok function, scanning your string in a loop until its end (i.e. when strtok returns NULL)
Roberto