Stacked Sum From an OLAP Cube

[DenizDuelec]

Lets say you have to plan capacities for two Teams per Week over two months.
For each week you have got target values and actual values in hours (h).
A table can look like this in 2008 for week 27 and 28:

Week 27:
Team A, actual 3h, target 2h
Team B, actual 4h, target 1h


Week 28:
Team A, actual 2h, target 2h
Team B, actual 2h, target 1h

Actual and Target are Measures in the cube. Lets build a chart that displays
the actual as bars and the target as points.
The * is the point for target/Team A and O is the point for target/Team B
The chart looks like this in beautiful ASCII:

4 -+- +----+
| | B |
3 -+- +----+ |
| | A | |
2 -+- | | | * +----+----+ *
| | | | | A | B |
1 -+- | | | O | | | O
| | | | | | |
0 -+---+----+----+-------------------+----+----+-------------
Year 2008
Week 27 Week 28

A = Team A
B = Team B
* = target/Team A
O = target/Team B

Now the QUESTION/PROBLEM I have got:
I want to Sum target/Team A and target/Team B in ONE Value that is called
"Overall target". But because I am using Data from an OLAP-Cube I cant Modify
data or the data-range. So it seems the calculated sum must be delivered from
the sube.
But the Measure "target value" is alway split up for Team A and Team B
separately and I cant stack it up.
Even if I create a variable in the Cube that sums up the target values for
the teams it gets split up in the chart.

The goal is that the chart looks like this:
4 -+- +----+
| | A |
3 -+- +----+ | @ @
| | | |
2 -+- | | | +----+----+
| | | | | A | B |
1 -+- | | | | | |
| | | | | | |
0 -+---+----+----+----------------- +----+----+-------------
Year 2008
Week 27 Week 28

A = Team A
B = Team B
@ = Overall target (so @ = * + O respectively 3 = 2 + 1

A long Question I know, but I would really be glad if you could help me out!