Use the STRTMP function and the new line character \n, followed by a physical carriage return
For example, suppose you have a set of variables declared as String and wish to concatenate them into a single variable, #var_main, separated by carriage returns. The Macro command would look like this:
#var_main=STRTMP("
%#var_1\n
%#var_2\n
%#var_3\n
%#var_4\n
%#var_5\n
%#var_6\n
%#var_7")]
These MUST be separated by physical carriage returns. Placing them all on the same line will output the literal \n and no new lines.
The following is a working example that you can copy and paste into a macro file. The last PAUSE command will display the #var_main variable on a seven row tall message box.
STRING: #var_1
STRING: #var_2
STRING: #var_3
STRING: #var_4
STRING: #var_5
STRING: #var_6
STRING: #var_7
STRING: #var_main
#var_1="1st var"
#var_2="2nd var"
#var_3="3rd var"
#var_4="4th var"
#var_5="5th var"
#var_6="6th var"
#var_7="7th var"
#var_main=STRTMP("
Line 1: %#var_1\n
Line 2: %#var_2\n
Line 3: %#var_3\n
Line 4: %#var_4\n
Line 5: %#var_5\n
Line 6: %#var_6\n
Line 7: %#var_7")]
PAUSE[TX=#var_main, SR=7]