If I am understanding your question correctly, I think you are asking this: for example A1 = 1, A2 = 2, A3 = 3,... and so on as numbering pertains.
Then if this is what you mean, try this: lets say you want to number A1 - A50, and you have 1, 2, 3, started already, then starting with, A3 (#3) highlight it through A50. Now on the menu bar, click Edit/Fill/Series, select (series in) either Row/Column, then (type) Linear <font color=red>most likely type</font color=red>, then click "OK".
If this doesn't answers your question let me know, otherwise, I have totally misunderstood. Hope this helps.
JC-------<*){{{>{~~~~~
Fisher of men