One way of doing it is by not using a cross-tab.  Create a formula for each month like:

frmJan08
=======
if month({Expenses.ExpenseDate}) = 1 and year({Expenses.ExpenseDate}) = 2008 then {Expenses.ExpenseValue} else 0

frmFeb08
=======
if month({Expenses.ExpenseDate}) = 2 and year({Expenses.ExpenseDate}) = 2008 then {Expenses.ExpenseValue} else 0

etc

Now set up a group of {Expenses.ExpenseType}

Create a summarising formula for the above functions:

frmTotJan08
=========
if SUM(@frmJan08,{Expenses.ExpenseType}) < 2000 then '' else ToText(SUM(@frmJan08,{Expenses.ExpenseType}))

frmTotFeb08
=========
if SUM(@frmFeb08,{Expenses.ExpenseType}) < 2000 then '' else ToText(SUM(@frmFeb08,{Expenses.ExpenseType}))

etc

Your group header should look something like:

{Expenses.ExpenseType}   {@frmTotJan08}  {@frmTotFeb08} etc

You should now suppress your detail section and the group footer and put the month headers above the columns.

Hope this helps.

theMessenger