Would it be all right to do some meditation besides the daily salat because I feel that it helps me to focus better I salat?
I would answer your question with an emphatic, “yes!” Meditation can be soothing for the mind and soul. It is a good way to get in tune with oneself. By all means I would encourage it. As a matter of fact the Prophet used to travel to Mount Hira and sit in the cave where he pondered and meditated and got away from monotonous noise of everyday life. However, people tend to take what is good in life and incorporate it within religion and all of the sudden somehow it becomes part of a ritual not established by the Prophet. This is something we should be cautious about. By no means am I suggesting that this is something that you do or would do, however, I feel compelled to mention it. As long as we can separate our personal likes, such as meditating or other beneficial activities, from our mandatory religious exercises then all should be well. However, again, I would emphasize that I personally feel that mediation, exercise and all that is beneficial to ones mind and body is a part of respecting the gift God has awarded us.
So go ahead meditate and when you pray may all that you ask for be rewarded to you in goodness.
I hope I have clarified the issue.
God knows best.