Force an expression: An expression can be used in a parameter that does not directly support it (except an OutputVar or InputVar parameter such as those of StringLen) by preceding the expression with a percent sign and a space or tab. This technique is often used to access arrays. For example:
FileAppend, % MyArray%i%, My File.txt
MsgBox % "The variable MyVar contains " . MyVar . "."
Loop % Iterations + 1
WinSet, Transparent, % X + 100
Control, Choose, % CurrentSelection - 1
Então, sugiro que você tente:
Click % 625 + %offset%, 575
Se isso não funcionar, pode ser porque a documentação do Click diz especificamente:
Since click does not support expressions, variables should be enclosed in percent signs.
Se isso acontecer, talvez valha a pena tentar MouseClick em vez disso, como sua documentação diz especificamente:
The x/y coordinates to which the mouse cursor is moved prior to clicking, which can be expressions.