read.table (again)

Dear R commnuity,

Thanks a lot for your help.
I want to read in tables, the problem is that the table is composed in a 
difficult way. In ariginal it looks like this:

669 736 842101610481029114711811166124312081128117611221026 9581024 992 
685 720 829 925 995 96010241057116611501104106410711092 983 908 989 904 
924 896 882 897 909 933 928 907 916 902
546 734 784 868 970 954 99210061012101610481045 9821057 989 914 956 960 
948 947 949 939 916 950
562 598 771 827 941 922 905 877 860 862 931 952 954 977 960 901 978 975 
970 950 973 953 958 931 912
558 593 725 786 884 866 838 797 815 802 809 822 853 833 863 852 903 
9861015 9841019 993 955 932 918 874 518 580 600 764 834 804 814 824 849 
831 939 757 769 790 809 892 89810251028104410371018 985 932
478 559 585 696 812 812 811 867 854 811 814 818 793 760 814 976 
957104510551067106410501005 948
465 528 567 619 703 828 824 830 851 824 823 873 826 787 787 
9791048105710621083108910841027 944

That is, that every 4 digits there is a new number, but when the number 
is > 999, R thinks of course that the number consists of more than 4 
digits. So, R can't read in the table.
Is there a way I can tell R, that every 4 digits, a new number begins?
I treif different things with "sep".
data <- read.table ("RA19930101.txt",header=F,sep=)

Thanks for your help again in this topic.
Sybille