How to take starting non empty value of variable (that doesn't mean L=1 always) however the data have some empty values in starting - Ferret

[sivaiahborra]

Dear All,
I have data, in which there are two dimensions that are "l - time (l=1:360)" and "m - no of events occurred (m=1:1753)" want to take starting value of a variable. I can take like this when there is no empty (-----) value in l=1
Eg. lon[l=1], but, the problem is every time my ''l'' value doesn't has with some value instead a empty or missing value.
so, when i do lon[l=1] for all m values. the results are coming as follows

m l=1 2 3 4 5 6 ...... etc upto 360
1 85 85.5 86 --- ---
2 --- --- 87 85 ---
3 --- --- 85 86 87
4 86 ---
.
.
.
.
etc upto 1753.

I need to list first non-empty l values for all m values somewaht like this
85
87
85
86

Thank you.