Yes...
INPUT "My message here ", myvariable
instead of INPUT "My message here "; myvariable
So just use a "," instead of a ";" in front of your variable. (Comma = no question mark. Semicolon = question mark.)
... but for string input, you can do it either way, and no question mark will appear...
LINE INPUT "No question mark "; myvariable$
LINE INPUT "No question mark ", myvariable$
Pete