[R] generating strings in a tricky order

[Taka Matzmoto]

Hi R users

I like to generate some strings (a character vector) in a special way like

If i have 5 variables

"002.001",
"003.001", "003.002",
"004.001", "004.002", "004.003",
"005.001", "005.002", "005.003", "005.004"

so the created string vector's elements are

"002.001", "003.001", "003.002","004.001", "004.002", "004.003","005.001", 
"005.002", "005.003", "005.004"

I tried to come up with for loop with two indexes (i and j) but I kept 
failing to generate that kind of order of strings. The order of the element 
in the character vector is very improtant.

Any advice or help would be appreciated

Thanks in advance

TM,