I have the same problem. After I started posting again I realized that was one of the problems that kept me from ataining my goals. With that in mind I added a new section to my "debt reduction plan" spreadsheet.
2500 150 2350
2350 150 (=)
The first number is my target goal to add to my retirement funds. The second number is what I know I can add per month. The third number is a formula that subtracts the second number from the first. I have first number on the second row set up to grab the amount from the third number above it. This way I can run the numbers all the way down the page for 12 months. What this shows me is that by the end of the year in order to achieve my goal of $2500 added to my retirement funds I need to find an additional 700 over the course of the year.
This allows me to treat my savings goal like a debt. If in Jan I am able to put 225 towards my retirement then I'll just change the 150 to 225 for that month and the formulas will change everything else on down the line. I'll instantly be able to see my progress for the end of the year.
Maybe this will help you also achieve your goals.
Cool idea! Thanks!