You could alter your cobol program to write the field as packed or as text in a text field.
You could write a cobol program to read the data and write to a new file with a packed field
You could copy this file to another file with a packed field - cpyf with *NOFMT
Assume column MIXED is CHAR(10) with positions 1-3 simple characters and positions 4-10 as PACKED(13,0). That is, the first three bytes can be separated with SUBSTR(MIXED,1,3) and the last seven bytes as SUBSTR(MIXED,4,7). The packed bytes can be exposed with HEX(SUBSTR(MIXED,4,7)). If the hex characters are x'0000000000001F', the decimal value is +1. The first 13 characters are all numeric, so the DEC() function can be used:
If there are decimal positions, the 13 hex characters can be separated with two SUBSTR() functions and CONCATed around a decimal point before processing with the outer DEC(). If the 14th character indicates a negative value, the expression can be multiplied by -1.
Create a VIEW to parse the compound field and to expose the sub-values. Use the view for sending values to a PC.