Sudhi recently asked me how to call an aspx page from a report and pass a parameter held in a textbox, or other control.
My solution is:
Drag a textbox control on to the report and enter the value "2005/07/28/408325" (without the the quotes) in to it. If this is a new report the textbox should be called textbox1 - visible in the properties dialogbox (usually bottom right) .
Right click on your textbox (even the cells in tables and matrixes contain textboxes) and choose Properties -> Advanced button -> Navigation Tab - 'Jump to URL:' textbox and press the 'fx' button on the right hand side. This takes you into the Expression Editor, here you enter the following in the 'Expression:' textbox on the right hand side.
="http://blogs.technet.com/mat_stephen/archive/" & reportitems!textbox1.value & ".aspx"
'Ok' all the dialogs back to your report - run the report and click on the textbox - heypresto!