You can whip something like this up in a spreadsheet such as Excel in seconds... For example, to compute what 76.5/95 represents if the assignment/exam is worth 35% of your grade you just enter 76.5 into a cell, hit tab and type "=((x/95)*100)*0.35" without the quotes/inverted commas. Hit enter and there ya go, your score converted into its weighting for the course. NB x = the name of the cell that your raw score was entered into, something like "D8".

Now for the GPA... that's awkward because every college/university has a different scale 4.0, 9.0, etc. and every university has a different way of calculating your GPA. The variables involved would need to be customizable in whatever solution you come up with (or someone comes up with). The two suggestions above work, but the GPA solution is university specific...