Multiply Values Between Database Field And Query Prompt Follow

I need to multiply the value from database field with the value given by user. I have tried following SQL command without success (Error S1000):

TABLE.FIELD * '?QueryPrompt' AS Nameforthefield

If I replace '?QueryPrompt' with number, I am able to run the SQL statement and print labels. What am I doing wrong? Is it even possible to use query prompt in SELECT statement?