assigning value

i am reading fiscal year/period (format - 010/2006) into Loc_var_range. after that i am reading var1(3) i.e. 010 . Now i have to subtract -1 from it i e. 009/2006

now i have to store that changes back into l_s_range.

i am trying this:

l_s_range-low(3) = (l_s_range-low(3))-1.

now what abt 2006? i have to assign that value also to l_s_range..how to do it?

Basically i have to assign 009/2006 into l_s_range. and loc_var_range is having value 010/2006.