how aobut having a separate variable that add+1 every time that the main varialbe adds+1
SO when the second variable gets to a number, you reset it back to 0 and then respawn enemies =)
like this
if player collects 1 coin
then*add+1 to "# of coins" variable
*add+1 to "# of coins to respawn enemy" variable
when "# of coins to respawn enemy" variable is = to 10 or >
then* set varaible "# of coins to respawn enemy" to 0
*respawn enemy at ???.X & ???.Y
does this work for you??