How to do word + consecutive/ random numbers with imacros?

I need to write a name with a random number or a consecutive number house12 house15 or house18 house19.... I do it:

4l TAG POS=1 TYPE=INPUT:TEXT FORM=ID:mForm ATTR=ID:checkoutm CONTENT=house 5l TAG POS=1 TYPE=INPUT:TEXT FORM=ID:mForm ATTR=ID:checkoutm CONTENT= EVAL("var randomNumber=Math.floor(Math.random()*100 + 1); randomNumber;")

Imacros write house but when write the random number delete house

How can i do for imacros don’t delete house? And how can i do yo write consecutive number house18, house19, house20....?

Thanks