There is Unicode 0307 (combining dot above) (looks like 1̇ ) or Unicode 0358 (combining dot above right) (looks like 1͘ ) but they don't perform very well for your task in my opinion. I think 0301 (combining acute accent) (looks like 1́ ) is better, although not very accurate.
For the bottom part 0316 (combining grave accent below) (looks like 1̖ ) is not very nice. You can try 0323 (combining dot below) (looks like 1̣).
You add the unicode characters after the normal letter and you can combine many of them (like 1̣́). Note that the results may vary among different types of fonts. The fonts I experience to support Unicode best are Arial and Times New Roman. I usually take Word, go to insert/symbol and try what looks best.
For the best results I recommend looking for a specialized font that has all the tones built in. Or create such a font by yourself. CorelDraw was able (in Version 6) to create fonts. I guess it still can in newer versions.